- University of Illinois at Urbana-Champaign, University Library
Armorial. Ownership. 66x95 mm. PORRO UNUM EST NECESSARIUM / WILLIAM NICHOLSON. Escutcheon, crest and banner with motto. Escutcheon azure parted by two bars argent, each charged with five ermine spots; three suns in splendor in chief; crest: crown or and lion's head with two ermine spots. Motto: "Porro unum est necessarium" = But one thing is necessary.
- Mallow (Ireland)
- 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