Does $G/\mathbb{Z} \cong \mathbb{Z}$ imply $G \cong \mathbb{Z}^2$?
135611
Extensions of $\mathbb{Z}$ by $\mathbb{Z}$
35188
Counterexample: $G \times K \cong H \times K \implies G \cong H$
12110
How are $2\mathbb{Z}\ncong3\mathbb{Z}$ different as rings?
2153
How to get a homomorphism from $\mathbb{Z}\to G$, for $G$ a non-trivial group?
84823
When is the group of units in $\mathbb{Z}_n$ cyclic?
68733
If $G/Z(G)$ is cyclic then $G$ is abelian – what is the point?
129750
Order of $SL_2(\mathbb{Z}/ n\mathbb{Z})$
132725
Is $\mathbb{Z}/\langle n\rangle$ cyclic and of order $n$?
31933
$x^2 = 1$ in the ring $\mathbb{Z}/n \mathbb{Z}$
118299
Show that $(\mathbb{Z}[x]/(x^{n+1}))^{\times}\cong \mathbb{Z}/2\mathbb{Z}\times\Pi_{i=1}^n\mathbb{Z}$
128701
Are $\mathbb{Q}$ or $\mathbb{Z}$ flat modules?
43645
Show that $G/H\cong S_3$
38549
$\mathbb{Q}(\sqrt{n}) \cong \mathbb{Q}(\sqrt{m})$ iff $n=m$
135046
Can this quick way of showing that $K[X,Y]/(Y-X^2)\cong K[X]$ be turned into a valid argument?
101602
consider the group $G=\mathbb Q/\mathbb Z$. For $n>0$, is there a cyclic subgroup of order n
35626
Is $(\mathbb{R}^2, lexicographic) \cong (\mathbb{R}, discrete)\times (\mathbb{R}, usual)$?
62566
Does $X\times S^1\cong Y\times S^1$ imply that $X\times\mathbb R\cong Y\times\mathbb R$?