Donald, P. & Garcia, E.F.J. (2019). Eurasian Skylark (Alauda arvensis). In: del
Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from https://www.hbw.com/node/57680
on 21 February 2019).