Loon, Hendrik Willem van, author
New York [t.p.] 1958
Buku Teks
Campbell, John R., author
McGraw-Hill , 1969
Buku Teks
edited by M. Marois
Pergamon Press, 1977
Buku Teks
Howells, William D., author
Doubleday, 1944
Buku Teks
Loon, Hendrick Van
Garden City Publishing Co.,Inc., 1926
Buku Teks