Princeton University Press, Princeton, N.J.. ISBN 0-691-04910-6*Harrap, Simon & Quinn, David (1996): "Tits, Nuthatches & Treecreepers".
Princeton University Press, Princeton, N.J.. ISBN 0-691-04910-6* Harrap, Simon & Quinn, David (1996): "Tits, Nuthatches & Treecreepers".