I loved this book, which I originally found in a used bookstore for $1.

The pseudonyms irritated me the first time I read it (this was pre-internet days) but when I rediscovered the book a few years back, I immediately hopped online to research, and ended up writing my own key inside the front cover of my sadly deteriorated $1 paperback — I do have a copy of the updated version now, which at the very least has a more appropriate cover.