Beck, Carlton E.
Penn International Textbook, 1969
Buku Teks
Galt, Anthony H.
John Wiley & Sons, 1976
Buku Teks
Lauder, Allan Frank
Faculty of Humanities University of Indonesia, 2015
Artikel Jurnal
Benda-Beckman, Franz von
1989
Artikel Jurnal
Manan Abdul
2013
Artikel Jurnal