Brame, Genevieve, author
Kogan Page, 2004
Buku Referensi
Larousse, 2005
Buku Referensi
Woworuntu, Rahma Pratiwi, author
Fakultas Ekonomi dan Bisnis Universitas Indonesia, 2022
UI - Tesis (Membership)
Spengler, Joseph J. (Joseph John), 1902-1991, author
Duke Univrsity Press, 1979
Buku Teks
Ehrmann, Henry W., author
Little, Brown & Co., 1968
Buku Teks