Budgerigars in colour their care and breeding /
Rutgers, Abram.
Rogers, Cyril H.(Cyril Harold),1907-.
Heinzel, K. J.
Vowles, R. A.
Previous English ed.: 1970. - Revised translation of: 'Handboek voor Kleurparkietenwekers'.
Bibliography: p.235-236. - Includes index.
Budgerigars.