Introductory textbooks in mathematics
Introductory Calculus textbook for physics?
How can I get a copy of a Canadian visa refusal letter? Find a file when you know its checksum? Multiple citations: citation order different to bibliography order I wish to cite several sources at once and sort my in-text citations in a different manner to how they appear in my bibliography. I want my citations to be sorted by year and my bibliography to be sorted by author. I am using BibLaTeX with Biber. I used  to achieve this with TeX Live 2015 but since upgrading to 2016 (as well as upgrading all my packages) this does not work.  Below is a minimal working example (with a second bibliography for illustrative purposes). I wish for the citations to be sorted ascending by year (2001, 2002, 2003) and the bibliographies to be sorted alphabetically (a, b, c) and descending by year (2003, 2002, 2001) respectively, but below is an image of the result; the bibliographies stay true to the desired sorting but the citations in-text are sorted descending by year.  If I remove the last \newrefcontext then everything (citations and bibliographies) is sorted alphabetically, and if I remove both \newrefcontexts then everything is sorted ascending by year (which was the option specified when originally calling BibLaTeX). It seems that the citations follow the last sorting referenced; ynt as per BibLaTeX options when both \newrefcontexts are removed or else whatever sorting is specified in the last \newrefcontext.  I am compiling in order pdflatex, biber, pdflatex, pdflatex and am on MacTeX.  It seems this would have worked as desired in TeX Live 2015 so is this a bug or has something changed which requires the citation sorting to be set in some other way?  \documentclass{article}  \usepackage[            backend=biber,            style=authoryear,            sorting=ynt,            sortcites,            ]{biblatex}  \usepackage{filecontents} \begin{filecontents}{lib.bib} @article{test1,   author = {b},   title = {b},   year=2003, } @article{test2,   author = {c},   title = {c},   year=2001, } @article{test3,   author = {a},   title = {a},   year=2002, } \end{filecontents}  \addbibresource{lib.bib}  \begin{document}      Hello World! \parencite{test1,test2,test3}      \newrefcontext[sorting=nyt]     \printbibliography      \newrefcontext[sorting=ydnt]     \printbibliography  \end{document}     Edit  I have a workaround but it's super crap: Typeset the document with global sorting=ynt, copy the pdf to another file, then typeset the document with global sorting=nyt; using a PDF editing tool (Apple's Preview suffices) cut the pages containing the bibliography with the desired sorting from one PDF and paste into the other. As I said super crap. I'm not sure if I'd even do this as I'd feel dirty, but it's a workaround nonetheless.  If a solution does not exist or this is a bug without a patch, then what would be similar but much better would be some kind of package (which probably doesn't exist) which only changes certain pages at a time within the PDF (while still actually 'compiling' the whole document so that all the citations are done). It might look something like:  % document preamble % ...  \usepackage{onlychange} \onlychangerange{10,12}  % Bibliography found on pages 10--12 % On next compilation will typeset all pages except 10--12  % ...   It's a long shot but maybe someone knows of such a package or this rambling has inspired an actual solution. Setup IIS 7.5 with multiple website bindings and SSL? On IIS 7.5 I am trying to achieve this with two websites:  Default Web Site is bound to:  (blank host header port 80 - http) (blank host header port 443 - https) go.example.com www71.example.com the IP address of go.example.com  2nd web site "Beta" is bound to:  beta.example.com (blank host header port 443 - https) * using blank only because it doesn't seem to be possible to    bind https to a named host header   And both need to work with SSL.  But I have these problems:   When I type in beta.example.com, I see the go.example.com site instead I can not seem to add the SSL binding to both websites at once (I have a single *.example.com wildcard certificate).  The beta site will not even start if I add the https binding to it.   This is how I have set it up:    What is the correct way to set it up? Examples in which the light maximizes the optical path length I posted a similar  about geodesics on Math.SE. Many sources ( for instance) claim that the light could maximize the optical path length in some cases. But I don't think it's actually true since between two points I can always imagine a path with arbitrary length. Therefore, or the light minimizes the optical length or it's stationary (neither maximum nor minimum). My question is: is the trajectory in red in the figure below a local minimum or a stationary curve?   If I'm wrong, please provide some examples which the light propagates in trajectory of maximum length. I just updated my iPhone 7 Plus to iOS 13 tonight and noticed that the post menu in the Stack Exchange app became close to unreadable, because the font/text is too large to be properly displayed. Luckily we can still recognize the icons...    (Yes, app development has been frozen for quite a while but the app continues to serve me well.) Now that El Capitan is "rootless", is there any way to get dtrace working? I've found dtrace to be an invaluable tool for debugging and troubleshooting all sorts of issues, not to mention the two dozen dtrace toolkit scripts shipped by Apple as part of El Capitan.  On El Cap though, running dtrace usually results in an endless spew of errors making dtrace all but useless. What is the difference between "I've been to China" and "I've gone to China"? Programmatically Create X509 Certificate using OpenSSL I have a C/C++ application and I need to create a X509 pem certificate containing both a public and private key.  The certificate can be self signed, or unsigned, doesn't matter.  I want to do this inside an app, not from command line.  What OpenSSL functions will do this for me?  Any sample code is a bonus! I have firefox already running on my system, and now in minimised state. What I want is to close the current tab running in firefox. How can I do this by simply using commands in terminal? What is the difference between using a colon and a semi-colon to join two sentences? I've seen a few questions on this site relating to semi-colons, which I believe I correctly understand, but what I'm not as clear about is colons.  For example:     The man ate the apple; it tasted good.   Is this not correctly also written as:     The man ate the apple: it tasted good.   In this case, what is the difference between the two sentences? How to disable creation of desktop workspaces on macbook?   Somehow they get created when I don't need them. [OS: Mojave] incoming mail just sits in the drop folder I want a document library to recieve email and store it so followed the steps outlined here:   I seem to be a bit stuck.  The mail's being delivered to the machine and it's appearing as .eml files in the drop folder, so SMTP and delivery is OK.    I assume Sharepoint's supposed to pick up the file, stick it in a library and delete it, but it doesn't, the mail file just sits there.  Nothing in the logs, obviously.  I haven't set this up before, how often does the timer service come about and pick up the mail? Need help to understand Maximum Likelihood Estimation for multivariate normal distribution? In maximum likelihood estimation for the parameter, mean $\mu$ of multivariate normal distribution, I end up with the following result:  $\mu_{MLE} = \dfrac{1}{n}\sum_{i=1}^n x_i$  The way I understand the above equation is the following way below, but I am wondering if the above equation means the following equation:  $\mu_{MLE} = \begin{bmatrix}\mu_1\\\mu_2\\\vdots\\\mu_n\end{bmatrix} = \begin{bmatrix}\dfrac{1}{n}\sum_{i=1}^n x_1\\\dfrac{1}{n}\sum_{i=1}^n x_2\\\vdots\\\dfrac{1}{n}\sum_{i=1}^n x_i\end{bmatrix} = \begin{bmatrix}E(X_1)\\E(X_2)\\\vdots\\E(X_n)\end{bmatrix} = \begin{bmatrix}\bar{X_1} \\ \bar{X_2} \\ \vdots \\ \bar{X_n}\end{bmatrix}$   And also Maximum Likelhood Estimation for $\Sigma$, I have ended up with the following equation:  $\Sigma_{MLE} = \dfrac{1}{n}\sum_{i=1}^n(x_i-\mu)(x_i-\mu)^T = \begin{bmatrix}Var(\sigma_{11}) &amp; Cov(\sigma_{12}) &amp; \dots &amp; Cov(\sigma_{1n}) \\ Cov(\sigma_{21}) &amp; Var(\sigma_{22}) &amp; \dots &amp; Cov(\sigma_{2n}) \\ {}&amp; \vdots&amp;  \\ Cov(\sigma_{n1}) &amp; Cov(\sigma_{n2}) &amp; \dots &amp; Var(\sigma_{nn})  \end{bmatrix}$  Somehow, I got the equation following some algebraic steps, but I can't see how this part, $\dfrac{1}{n}\sum_{i=1}^n(x_i-\mu)(x_i-\mu)^T$, works and produces the covariance matrix. Hope to hear some explanations. Are black hole regarded as baryonic matter in cosmology? Black holes do not have any property as baryonic or non-baryonic matter, as is stated by the no-hair theorem. Regarding conventional theories, in different models of cosmology, like Lambda-CDM, are black holes regarded as baryonic matter, and does the black hole matter significantly affect the baryonic density? Clicking on tags in global search results is broken Desktop folders won't open with clean install of 18.04 Moving one object causes other to move another (already tried unlinking) How can I change the font of the top bar without changing the shell theme? I am using Ubuntu GNOME 17.04. I want to change the font of the GNOME top bar from the default font by Adapta to Fira Sans. I already have all the fonts, I just want to change the font of the top bar so it doesn't look out of place compared to everything else. Our company has multiple domains set up with one website hosted on each of the domains. At this time, each domain has its own authentication which is done via cookies.   When someone logged on to one domain needs to access anything from the other, the user needs to log in again using different credentials on the other website, located on the other domain.   I was thinking of moving towards single sign on (SSO), so that this hassle can be eliminated. I would appreciate any ideas on how this could be achieved, as I do not have any experience in this regard.  Thanks.  Edit: The websites are mix of internet (external) and intranet (internal-used within the company) sites.