Simpson, W.O.
Stanley Thornes, 1988
Buku Teks
Gottschalk, Louis, author
Yayasan Penerbit UI, 1975
Buku Teks
edited by Fritz Stern
Meredian Books, 1959
Buku Teks
edited by Fritz Stern
Merridian Book, 1972
Buku Teks
Thompson, James Westfall, author
Macmillan, 1958
Buku Teks