Necessary and Sufficient Condition for Existence of Isomorphism between $\mathbb{Z}_{nm}$ and $\mathbb{Z}_n\bigoplus \mathbb{Z}_m$
28362
Product of two cyclic groups is cyclic iff their orders are co-prime
45627
Find a sub-ring of M(2, $\mathbb{Q}$) which is isomorphic to $\mathbb{Q}$
30178
Homeomorphism $(\mathbb{CP}^1)^m/S_m \overset{\sim}{\to} \mathbb{CP}^m$?
79734
Is every sub-lattice of $\mathcal P(X)$ isomorphic to a sub-lattice of $\mathcal P(X')$ containing singleton sets?
6385
Minimal counterexamples of the isomorphism problem for integral group rings
59134
Proving idempotent elements in $\mathbb{Z}_n$
117131
Canonical Isomorphism Between $\mathbf{V}$ and $(\mathbf{V}^*)^*$
13764
Homomorphisms from $\mathbb{Z} \rightarrow S_3$.
128443
Isomorphism between finite groups
116594
Finite fields are isomorphic
86174
Finding an isomorphism between these two finite fields
98587
$\mathbb Z [X] / (X)$ isomorphic to $\mathbb Z[X] / (X+1)$ isomorphic to $\mathbb Z [X] / (X+2015)$
13761
Automorphisms in $\mathbb{Z}_n$
89167
Cardinality of equivalence relations in $\mathbb{N}$
41846
$(\mathbb{R}^n,\|\cdot\|_{p})$ is isometrically isomorphic to $(\mathbb{R}^n,\|\cdot\|_{q})$ iff $p=q,$
37351
Group of Order $p^2$ Isomorphic to $\mathbb{Z}_{p^2}$ or $\mathbb{Z}_{p}$ $\times$ $\mathbb{Z}_{p}$
51687
Is the set $ \ (\mathbb{Z}_p \setminus \mathbb{Z}) \cap \mathbb{Q}$ non-empty?