The birds of Africa,.
London,Published for the author by R.H. Porter (18 Princes Street, Cavendish Square, W.),1896-1912..
biodiversitylibrary.org/page/14023276
Description: Photograph taken by Christiaan Kooyman on 23 December 2005 in Nanyuki, Kenya. Date: 23 December 2005. Source: Own work. Author: Christiaan Kooyman.