Hopkins, John A., author
Iowa State University Press, 1962
Buku Teks
Smith, Mike (J. Mike), author
Australia Brodcasting Corporation , 1986
Buku Teks
Ronny, author
Fakultas Ekonomi dan Bisnis Universitas Indonesia, 2014
UI - Tesis (Membership)
Stefano Zora Parameswara, author
2019
UI - Skripsi (Membership)
Jahne, Johannes, author
Leipzig , 1966
Buku Teks