Ballard, Robert D., author
National Geographic Society, 1983
Buku Referensi
Bowler, Sue, author
Erlangga, 2003
Buku Teks
Chester, Roy, author
American Management Association, 2008
eBooks
Faundra Ihsan Pratama, author
Fakultas Teknik Universitas Indonesia, 2020
UI - Skripsi Membership
Muhammad Ihsan Alamsyah, author
Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Indonesia, 2020
UI - Skripsi Membership