Garg, Arunesh, author
Gian Jyoti Institute of Management & Technology, 2013
Artikel Jurnal
Guru Nanak National College, India, 2012
Artikel Jurnal
Muhammad Iqbal, author
Fakultas Ekonomi dan Bisnis Universitas Indonesia, 2013
UI - Skripsi Membership
World Bank
World Bank, 1999
Buku Teks
Jan Hendrik Rapar, author
Trisakti University, 1999
Buku Teks