E. H. Forbush, 1927, _Birds of Mass._, etc., Vol. 2, p. 34 (ruffed grouse). D. L. Serventy and H. M. Whittell, 1948, _Birds of Western Australia_, pp. 73, 74 (Australian pigeons). R. Meinertzhagen, 1912, _Ibis_, p. 96 (Mauritius pigeon).