$\mathbb{Z}_{p^2}$ and $\mathbb{Z}_p\times \mathbb{Z}_p$
135241
Show that $\mathbb{Z}/n^2\mathbb{Z}$ is not isomorphic to other group
40490
Birational isomorphism $\mathbb{P}^n\times \mathbb{P}^m\to \mathbb{P}^{n+m}$
109596
Isomorphism from $\mathrm{Aut}(\mathbb{Z}/2\mathbb{Z}\times \mathbb{Z}/2\mathbb{Z})$ to $S_3$
75127
Group $G$ of order $p^2$: $\;G\cong \mathbb Z_{p^2}$ or $G\cong \mathbb Z_p \times \mathbb Z_p$
75068
subgroups of $\mathbb Z / 2 \mathbb Z \times \mathbb Z / 2 \mathbb Z$
38507
Show that $\mathbb{Q}\times \mathbb{Q}$ is denumerable
11000
Fundamental group of $\mathbb{R}^2 \setminus (\mathbb{Z} \times \{0\})$
27472
Prove that $PSL(2,\mathbb{Z})$ is free product of $C_2$ and $C_3$
16559
Difference between $\mathbb{Z}/n\mathbb{Z}$ and $\mathbb{Z}_n$
115876
$D_6 \cong D_3\times \mathbb Z_2$
143069
What are the direct summands in $\mathbb{Z}^n$?
138058
Prove that $\mathbb Z_{m}\times\mathbb Z_{n} \cong \mathbb Z_{mn}$ implies $\gcd(m,n)=1$.
99884
Are $\mathbb{Q}_p$ and $\mathbb{Q}_q$ homeomorphic?
146990
How to find the number of automorphisms on $\mathbb Z_2\times \mathbb Z_4$
94296
Classifying the factor group $(\mathbb{Z} \times \mathbb{Z})/\langle (2, 2) \rangle$
90239
$\mathbb{Z} \times \mathbb{Z}$ is cyclic.
100439
Proving that a Galois group $Gal(E/Q)$ is isomorphic to $\mathbb{F}_p^\times$