\documentclass[12pt]{article}
\usepackage{amsmath,amssymb,amsfonts}
\begin{document}
A group $G$ is called co-Dedekindian if every subgroup of $G$ is invariant under all central automorphisms of $G$. In this paper we give some necessary conditions for certain finite p-groups with non-cyclic abelian second centre to be co-Dedekindian. We also classify 3-generator co-Dedekindian finite p-groups which are of class 3, having non-cyclic abelian second centre with $|\Omega_1(G^p)|=p$.
\end{document}