Published in Raptor Research, in 1981, in volume 15, issue 1, pages 1-3

Published in Raptor Research, in 1981, in volume 15, issue 1, pages 12-18

Published in Raptor Research, in 1981, in volume 15, issue 1, pages 19-22

Published in Raptor Research, in 1981, in volume 15, issue 1, pages 22

Published in Raptor Research, in 1981, in volume 15, issue 1, pages 23-30

Published in Raptor Research, in 1981, in volume 15, issue 1, pages 31-32

Published in Raptor Research, in 1981, in volume 15, issue 2, pages 42-45

Published in Raptor Research, in 1981, in volume 15, issue 2, pages 45-48

Published in Raptor Research, in 1981, in volume 15, issue 2, pages 48-52

Published in Raptor Research, in 1981, in volume 15, issue 2, pages 53-57

Published in Raptor Research, in 1981, in volume 15, issue 2, pages 58-64

Published in Raptor Research, in 1981, in volume 15, issue 3, pages 68-82

Published in Raptor Research, in 1981, in volume 15, issue 3, pages 82-85

Published in Raptor Research, in 1981, in volume 15, issue 3, pages 86-88

Published in Raptor Research, in 1981, in volume 15, issue 3, pages 89-93

Published in Raptor Research, in 1981, in volume 15, issue 3, pages 94-95

Published in Raptor Research, in 1981, in volume 15, issue 4, pages 97-107

Published in Raptor Research, in 1981, in volume 15, issue 4, pages 108-112

Published in Raptor Research, in 1981, in volume 15, issue 4, pages 113-120

Published in Raptor Research, in 1981, in volume 15, issue 4, pages 120

Published in Raptor Research, in 1981, in volume 15, issue 4, pages 121

Published in Raptor Research, in 1981, in volume 15, issue 4, pages 122

Published in Raptor Research, in 1981, in volume 15, issue 4, pages 123-124