Mueller, Francis J., author
Dickenson , 1966
Buku Teks
Merchant, Charles J., author
Harper & Row, 1971
Buku Teks
Gager, William A., author
Macmillan, 1968
Buku Teks
Gallian, Joseph A., author
D.C. Heath, 1990
Buku Teks
Griswold, Alice L., author
Holt, Rinehart and Winston, 1961
Buku Teks