"Trixie Belden: Schoolgirl Shamus"
James Keeline's Paper: Keeline is the author of numerous articles and presentations on the history of children's literature. Please be warned, however, that there are many inaccuracies in the paper, illustrating that Mr. Keeline is not a true Trixie Belden fan (that he charges from $100-500 for Trixie books in his bookstore also illustrates this fact).
Schoolgirl Shamuses, Incorporated
by Melanie Knight, 598 pages. This book reportedly has a wealth of information about teenage sleuths, including Trixie Belden, Ginny Gordon, Robin Kane, and Meg Duncan.
The Girls' Series Companion, 1997 Edition
by The Society of Phantom Friends, 634 pages. This book has descriptions and listings for nearly every Girls' American Juvenile Series in hardcover and paperback.