Published in Journal für Ornithologie, in 1876, in volume 24, pages 79-84

Created: 2014-09-04, modified: 2014-09-04

Published in The Great Basin Naturalist, in 1983, in volume 43, pages 425-428

Created: 2017-11-16, modified: 2017-11-16

Published in Journal of Raptor Research, in 1988, in volume 22, issue 4, pages 107-115

Created: 2017-04-07, modified: 2017-04-07

Published in Journal of Raptor Research, in 1988, in volume 22, issue 4, pages 101-106

Created: 2017-04-07, modified: 2017-04-07

Published in Journal für Ornithologie, in 1888, in volume 36, pages 313-571

Created: 2014-09-04, modified: 2014-09-04