\documentclass[12pt]{article}
\usepackage{amsmath,amssymb,amsfonts}
\begin{document}
In this paper we study the probability that the commutator
of two randomly chosen elements in a finite group is equal to a
given element of that group. Explicit computations are obtained for
groups $G$ which $|G'|$ is prime and $G' \leq Z(G)$ as well as for
groups $G$ which $|G'|$ is prime and $G' \cap Z(G)=1$. This paper
extends results of Rusin [see D. J. Rusin, What is the probability
that two elements of a finite group commute? Pacific J. Math. 82
(1979), no. 1, 237-247].
\end{document}