Published in Raptor Research, in 1977, in volume 11, issue 3, pages 49-58

Published in Raptor Research, in 1977, in volume 11, issue 3, pages 59-62

Published in Raptor Research, in 1977, in volume 11, issue 3, pages 62-66

Published in Raptor Research, in 1977, in volume 11, issue 3, pages 66

Published in Raptor Research, in 1977, in volume 11, issue 3, pages 67-71

Published in Raptor Research, in 1977, in volume 11, issue 3, pages 71-72

Published in Raptor Research, in 1977, in volume 11, issue 3, pages 73

Published in Raptor Research, in 1977, in volume 11, issue 4, pages 87-96

Published in Raptor Research, in 1977, in volume 11, issue 1-2, pages 1-46

Published in Raptor Research, in 1977, in volume 11, issue 1-2, pages 28-48