$PSL(2, \Bbb{Z})\cong \Bbb{Z}_2 \ast \Bbb{Z}_3$
27472
Prove that $PSL(2,\mathbb{Z})$ is free product of $C_2$ and $C_3$
137285
Prove $\mathbb{Z}_2 \times \mathbb{Z}_2$ is not isomorphic to $\mathbb{Z}_4$
107163
Proof that $S_3$ isomorphic to $D_3$
98284
show $\Bbb Z_6 \cong \Bbb Z_3 \times \Bbb Z_2 $.
93169
Show that $(\mathbb Z[x],+)$ and $(\mathbb Q_{>0},\cdot)$ are isomorphic groups
13764
Homomorphisms from $\mathbb{Z} \rightarrow S_3$.
50130
$\operatorname{Aut}(V)$ is isomorphic to $S_3$
126859
$\Bbb Z^\ast$ What is this notation?
78263
Prove $GL_n(\Bbb{R})/SL_n(\Bbb{R}) \cong \Bbb{R}^\times$
157031
Express $x^8-x$ as a product of irreducibles in $\Bbb Z_2[x]$
75127
Group $G$ of order $p^2$: $\;G\cong \mathbb Z_{p^2}$ or $G\cong \mathbb Z_p \times \mathbb Z_p$
86224
The root system of $sl(3,\mathbb C)$
30752
Proof of $(\mathbb{Z}/m\mathbb{Z}) \otimes_\mathbb{Z} (\mathbb{Z} / n \mathbb{Z}) \cong \mathbb{Z}/ \gcd(m,n)\mathbb{Z}$
43645
Show that $G/H\cong S_3$
128711
$(\Bbb Z\oplus \Bbb Z)[X] \not\cong \Bbb Z[X]\oplus \Bbb Z[X]\,$?
23037
Computing the order of $\mathrm{SL}_2(\mathbb F_p)$ as the kernel of $\mathrm{GL}_2(\mathbb F_p)$
4648
Proving that $\mathbb{Z}_m\oplus \mathbb{Z}_n \cong \mathbb{Z}_d\oplus \mathbb{Z}_l $ as groups, where $l=\mathrm{lcm}(m,n)$ and $d=\gcd(m,n)$