Artikel Jurnal
Soohoo, Ronald F., author
Harper & Row, 1965
Buku Teks
Morosanu, C.E., author
Elsevier, 1990
Buku Teks
edited by Georg Hass, Maurice H. Francombe, John L. Vossen
Academic Press , 1982
Buku Teks
Syarfina Andini, author
2018
UI - Skripsi (Membership)