A graph is a cactus if every edge is part of at most one cycle.
A well-known theorem is as follows.
Theorem 1. Let $G$ be a cactus. Then $|E(G)|\le \lfloor \frac{3(|V(G)|-1)}{2} \rfloor$.
I would like to ask from which formal literature this theorem was originally derived. I want to quote it in my manuscript. So far as I know, it is as an exercise in West's textbook “ D B. West Introduction to Graph Theory [M]. Upper Saddle River: Prentice-Hall, 2001.”.
In addition, are there any review articles for this graph class?