India 2013. Sea Swallow. 2014, 63: 46–48. Robertson, Christopher John Rutherford; Bell, Ben D. Seabird status and conservation in the New Zealand region
the zones 10 deg to 20 deg and 30 deg to 50 deg. Contributions from the Rutherford Observatory of Columbia University New York. 1952, 32: 1. Bibcode:1952CoRut