- University of Illinois at Urbana-Champaign, University Library
Pictorial. Ownership. 100x145 mm. TIBI SEMPER / R. B. Gorgon's head on back of tortoise. Initials on banner. Motto: "Tibi semper" = Always to you.
- Rare Book and Manuscript Library, University of Illinois at Urbana-Champaign; For more information, please contact the Rare Book and Manuscript Library: https://illinois.edu/fb/sec/7016277