Sihombing, Tumpal M.
Fakultas Ekonomi dan Bisnis Universitas Indonesia, 2009
UI - Tesis (Open)
Mehta, J.K.
Caitanya Publishing House, 1967
Buku Teks
Burns, Arthur Edward
Harcourt, Brace, 1948
Buku Teks
Hogendorn, Jan S.
Prentice-Hall, 1995
Buku Teks
Chang, Semoon
Allyn and Bacon, 1990
Buku Teks