Certo, Samuel C.
Irwin , 1995
Buku Teks
Stuart, Peter C.
Far horizon books, 1989
Buku Teks
Firnberg, David
George Allen and Unwin , 1973
Buku Teks
Li, David H., author
McGraw-Hill, 1968
Buku Teks
Ardis, Patrick M., author
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Buku Teks