APA-referens (7:e uppl.)
Guppy, C. S., & Shepard, J. (2001). Butterflies of British Columbia: Including western Alberta, southern Yukon, the Alaska Panhandle, Washington, northern Oregon, northern Idaho, northwestern Montana. UBC Press.
Chicago-referens (17:e uppl.)
Guppy, Crispin Spencer, och Jon Shepard. Butterflies of British Columbia: Including Western Alberta, Southern Yukon, the Alaska Panhandle, Washington, Northern Oregon, Northern Idaho, Northwestern Montana. Vancouver: UBC Press, 2001.
MLA-referens (9:e uppl.)
Guppy, Crispin Spencer, och Jon Shepard. Butterflies of British Columbia: Including Western Alberta, Southern Yukon, the Alaska Panhandle, Washington, Northern Oregon, Northern Idaho, Northwestern Montana. UBC Press, 2001.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.