Day, A. Grove (Arthur Grove), 1904-1994, author
Twayne, 1974
Buku Teks
FitzGerald, Robert David, 1902-, author
University of Queensland Press, 1987
Buku Teks
Portland, Or. : F. Cass, 1995
Buku Teks
Robert, D.S.
Harper & Row, 1981
Buku Teks
Chellis, Robert D
McGraw-Hill Company, 1961
Buku Teks