Gamer, Robert E., author
Allyn and Bacon, 1976
Buku Teks
edited by S.N. Eisenstadt
Little, Brown and Company, 1968
Buku Teks
Khushalani, Yougindra
Martinus Nijhoff Publishers, 1982
Buku Teks
Swarup, Jagadish
N.M.Tripathi Private Ltd., 1975
Buku Teks
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