oldbookillustrations:Crested titmouse. Parus cristatus, Linn.Keulemans, John Gerrard; from Coloured
oldbookillustrations:Crested titmouse. Parus cristatus, Linn.Keulemans, John Gerrard; from Coloured figures of the birds of the British islands vol. 2, by Powys, Thomas 4th Baron Lilford (issued by); London, 1885-1897. (Source: Biodiversity Heritage Library, the Internet Archive) -- source link