Olson, C. V. and D.P. Arsenault. 2000.  Differential winter distribution by sex of Rough-legged Hawks (Buteo lagopus) in western North America.  Journal of Raptor Research 34:157-166.

Olson, C. V. and  S. A. H. Osborn.  2000.  First North American record of a melanistic female Northern Harrier. Journal of Raptor Research 34: 58-59.