Artikel Jurnal
edited by Don Nix and Rand Spiro
Lawrence Erlbaum Associates, 1990
Buku Teks
Daniels, Klaus, author
Birkhauser, 1987
Buku Teks
Englert, Robert D., author
McGraw-Hill, 1990
Buku Teks
Ria Utami, author
Fakultas Ekonomi dan Bisnis Universitas Indonesia, 2014
UI - Skripsi Membership