Higgins, L. G., & Riley, N. D. (1970). A Field guide to the butterflies of Britain and Europe QL555 .A1 H. Collins.
Lua i Stíl Chicago (17ú heag.)Higgins, Lionel George, agus Norman Denbigh Riley. A Field Guide to the Butterflies of Britain and Europe QL555 .A1 H. London: Collins, 1970.
Lua MLA (9ú heag.)Higgins, Lionel George, agus Norman Denbigh Riley. A Field Guide to the Butterflies of Britain and Europe QL555 .A1 H. Collins, 1970.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.