Theriault, F. (2000). Hertwig & Co: Archives ; 1890-1937. Gold Horse Publishing.
Lua i Stíl Chicago (17ú heag.)Theriault, Florence. Hertwig & Co: Archives ; 1890-1937. Annapolis, Maryland: Gold Horse Publishing, 2000.
Lua MLA (8ú heag.)Theriault, Florence. Hertwig & Co: Archives ; 1890-1937. Gold Horse Publishing, 2000.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.