Sharan, P.
Metropolitan, 1984
Buku Teks
Hardgrave, Robert L., author
Harcourt College, 2000
Buku Teks
Hardgrave, Robert L., author
Harcourt, Brace, 1970
Buku Teks
Kothari, Rajni, author
Little, Brown, 1970
Buku Teks
Deutsch, Karl Wolfgang, 1912-1992, author
Houghton Mifflin, 1970
Buku Teks