It is well-known that if $G$ be an elementary abelian group of order $p^n$, then $\mathrm{Aut}(G)\cong $ GL($n,p$) (linear group of degree $n$ over $\mathbb{Z}_p)$.
My question is about the automorphism group of $G = \mathbb{Z}_{p^2} \times \mathbb{Z}_p \times \cdots \times \mathbb{Z}_p$. There exist a number of articles from which the order of $|\mathrm{Aut}(G)|$ can be easily obtained( Theorem 3.2 ).
I want to know if anyone knows any references that stuy or contain any information about the exact structure or exact form of elements of $\mathrm{Aut}(\mathbb{Z}_{p^2} \times \mathbb{Z}_p \times \cdots \times \mathbb{Z}_p)$?