1. Numbering of primaries;Ashmole;Auk,1961
2. Ginn , H. B. Melville , D. S. 1983 Moult in birds
3. An approach to the study of moults and plumages;Humphrey;Auk,1959
4. Lenton , G. M. 1980 Ecology of Barn Owls Tyto alba in the Malay peninsula with reference to their use in rodent control Unpubl. Ph.D. Thesis University of Malaysia
5. Über die Grossgefielder-Mauser der Schleiereule und Waldkranz;Piechocki;J. Ornithol.,1960