Published in Raptor Research, in 1973, in volume 7, issue 2, pages 25-31
Published in Raptor Research, in 1973, in volume 7, issue 2, pages 32-38
Published in Raptor Research, in 1973, in volume 7, issue 2, pages 39-42
Published in Raptor Research, in 1973, in volume 7, issue 2, pages 49-54
Published in Raptor Research, in 1973, in volume 7, issue 2, pages 62
Published in Raptor Research, in 1973, in volume 7, issue 2, pages 63
Published in Raptor Research, in 1973, in volume 7, issue 3/4, pages 73-77
Published in Raptor Research, in 1973, in volume 7, issue 3/4, pages 78-96
Published in Raptor Research, in 1973, in volume 7, issue 3/4, pages 107-108
Published in Raptor Research, in 1973, in volume 7, issue 3/4, pages 109-111
Published in Raptor Research, in 1973, in volume 7, issue 3/4, pages 112-115