Reilly, Frank K.
The Dryden Press, 1994
Buku Teks SO
Dar, Usha
Sterling Publishers Pvt.Ltd., 1979
Buku Teks SO
Curley, Anthony J.
Harper & Row , 1979
Buku Teks SO
Wendt, Paul F.
The University of California, 1966
Buku Teks SO
Manurung, Apriandi
2017
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