On faithful quasi-permutation representations of $VZ$-groups and Camina $p$-groups

For a finite group $G$, we denote by $\mu (G)$ and $c(G),$ the minimal degree of faithful permutation representation of $G$ and the minimal degree of faithful representation of $G$ by quasi-permutation matrices over the complex field $\mathbb{C}$. In this paper we examine $c(G)$ for $VZ$-groups and Camina $p$-groups.