McCaque, James
Harper & Row Publishers , 1964
Buku Teks
Stapledon, Olaf
Penguin Books, 1938
Buku Teks
Davison, Frank Dalby, 1983-1970, author
Angus and Robertson, 1973
Buku Teks
edited by Penny Kaganoff and Susan Spano
Harcourt Brace & Company, 1997
Buku Teks
Clark, Wilfrid E. Le Gros, author
Holt, Rinehart and Winston, 1967
Buku Teks