Suborder – Accipitres. [w:] Management Guidelines for the Welfare of Zoo Animals – FALCONIFORMES [on-line]. WildPro, 2000. [zarchiwizowane z tego adresu (2014-02-03)].
Suborder – Accipitres. [w:] Management Guidelines for the Welfare of Zoo Animals – FALCONIFORMES [on-line]. WildPro, 2000. [zarchiwizowane z tego adresu (2014-02-03)].