Report number 128 from Kvismare Bird Observatory:
Observations of a ZZW female in a natural population - implications for avian sex determination.
Arlt D, Bensch S, Hansson B, Hasselquist D, Westerdahl H
Article in journal
Proceedings of the Royal Society, London, B (suppl) . 2004. Volume 271, page(s) s249-s251.