S.B. Hagen, H.P. Leinaas & H.M. Lampe (2003) "Responses of great tits Parus major to small tortoiseshells Aglais urticae in feeding trials; evidence of aposematism" Ecological Entomology vol. 28, nr. 4, pp. 503-509. DOI:10.1046/j.1365-2311.2003.00522.x
jstor.org
A.S. Pullin (1987) "Changes in leaf quality following clipping and regrowth of Urtica dioica, and consequences for a specialist insect herbivore, Aglais urticae" Oikos vol. 49, pp. 39-45. Link
