I.: Falla, R.A.; Sibson, R.B.: A Field Guide to the Birds of New Zealand. London, Collins 1966. cloth w. dust jacket. / II.: Falla, R.A.; Sibson, R.B.; The new Guide to the Birds of New Zealand. Auckland, Collins 1978. Hardback. ISBN 0002196220 / III.: Harper, Peter; Kinsky, F.C.: New Zealand Albatrosses and Petrels. An Identification Guide. Wellington, Biological Society, Victoria Univ. of Wellington 1974. Pbk.