Carr, V. A. V. (1959). Mule and hybrid birds. London: Cage birds.
Dyfyniad Arddull ChicagoCarr, V. A. V. Mule and Hybrid Birds. London: Cage birds, 1959.
Dyfyniad MLACarr, V. A. V. Mule and Hybrid Birds. London: Cage birds, 1959.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.