R. C. Murphy, 1936, _Oceanic Birds of South America_, Vol. 1, p. 374 (penguins). F. Harper, 1953, _Amer. Midland Nat._, Vol. 49, p. 6 (birds and lichens). H. W. Feilden, 1877, _Zoologist_, Vol. 1, p. 319 (arctic-fox gardens).