Strayer, Joseph R. (Reese), 1904-1987
Harcourt Brace Jovanovich, [date of publication not identified]
Buku Teks
Hocker, Joyce L.
Win C. Brown , 1944
Buku Teks
Keedy, Mervin L., author
Addison-Wesley Pub. Co. , 1965
Buku Teks
Kohler, Eric L., author
Prentice-Hall, 1957
Buku Teks
Kohls, Richard L.
New York, N.Y. Macmillan c.1972,
Buku Teks