Todaro, Michael P., author
Erlangga, 1994
Buku Teks
Euromonitor, 1989
Buku Teks
Misbahol Yaqin, author
Fakultas Ekonomi dan Bisinis Universitas Indonesia, 2022
UI - Tesis (Membership)
Lewis, William Arthur, author
University of Ghana by the Ghana Pub, 1971
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Little, Ian M.D.
Basic Books , 1982
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