1. Brain size, development and metabolism in birds and mammals;Bennett P. M.;J. Zool.,1985
2. Active and resting metabolism in birds: allometry, phylogeny and ecology;Bennett P. M.;J. Zool.,1987
3. Cramp S. (and co-editors) 1977^1994 Birds of the Western Palearctic. Nine volume series. Oxford University Press.
4. del Hoyo J. Elliott A. & Sargatal J. 1992^1997 Handbook of the birds of the world vol. 1^4. Barcelona: Lynx Editions.
5. Dunning J. B. 1993 CRC handbook of avian body masses. London: CRC Press.