Ching, Francis D.K., 1943-
John Wiley & Sons, 2003
Buku Teks
Martin, C. Leslie
Macmillan, 1970
Buku Teks SO
Goodban, William T.
McGraw-Hill, 1979
Buku Teks
White, Edward T.
Florida University, [19?-]
Buku Teks
Goodban, William T.
McGraw-Hill, 1979
Buku Teks