APA-referens (7:e uppl.)

Gosler, A., Gosler, A., & Perrins, C. (1987). Some aspects of bill morphology in relation to ecology in the great tit Parus major.

Chicago-referens (17:e uppl.)

Gosler, A., Andrew Gosler, och C. Perrins. Some Aspects of Bill Morphology in Relation to Ecology in the Great Tit Parus Major. 1987.

MLA-referens (9:e uppl.)

Gosler, A., et al. Some Aspects of Bill Morphology in Relation to Ecology in the Great Tit Parus Major. 1987.