My birds in freedom & captivity, Hubert D. Astley, London :J. M. Dent, 1900.
biodiversitylibrary.org/page/13687960
The Avicultural magazine, Being the Journal of the Avicultural Society for the study of British and foreign birds in freedom and captivity. Edited by the Marquess of Tavistock. Fourth Series, Volume II. January 1924 to December 1924.
biodiversitylibrary.org/page/56200435
Gray lady and the birds
New York,The Macmillan company, 1907
www.biodiversitylibrary.org/item/45945
