Citazione Stile APA (7a Edizione)

Higgins, L. G., & Riley, N. D. (1970). A Field guide to the butterflies of Britain and Europe QL555 .A1 H. Collins.

Citazione stile Chigago Style (17a edizione)

Higgins, Lionel George, e Norman Denbigh Riley. A Field Guide to the Butterflies of Britain and Europe QL555 .A1 H. London: Collins, 1970.

Citatione MLA (9a ed.)

Higgins, Lionel George, e Norman Denbigh Riley. A Field Guide to the Butterflies of Britain and Europe QL555 .A1 H. Collins, 1970.