All letters for this project have been sourced from the Comics Collection at Michigan State University (MSU), part of the larger Dr. Stephen O. Murray and Dr. Keelung Hong Special Collections, established in 1962. MSU's Comics collection houses ~350,000 comic books, making it the largest publicly available collection of its kind worldwide, making projects such as these possible.

More specifically, this project's letters were sourced from MSU Special Collections' comprehensive materials on the Warrior anthology magazine and complete materials on Eclipse Comics' Miracleman. These materials are open to non-affiliated and other public researchers under the land grant mission of the University, with specific reading access contingent on prior appointment with the Libraries staff.

This project extends its appreciation to Jason Larsen, the Comics Librarian at MSU, and the staff at MSU Libraries and the MSU Office of Copyright for their support.