References
- Morant , P. D. 1979 . Twentieth Ringing Report for southern Africa . Ostrich , 50 : 83 – 87 .
- Morant , P. D. 1980 . Twenty-first Ringing Report for southern Africa . Ostrich , 51 : 204 – 214 .
- Vernon , C. J. 1977 . Nineteenth Ringing Report for southern Africa . Ostrich , 48 : 106 – 109 .