Cita APA (7th ed.)
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.
Cita Chicago (17th ed.)
Guppy, Crispin Spencer, i 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.
Cita MLA (9th ed.)
Guppy, Crispin Spencer, i Jon Shepard. Butterflies of British Columbia: Including Western Alberta, Southern Yukon, the Alaska Panhandle, Washington, Northern Oregon, Northern Idaho, Northwestern Montana. UBC Press, 2001.
Atenció: Aquestes cites poden no estar 100% correctes.