Knapp, Stephen
Pockport Pub, 1998
Buku Referensi
King, Carol Soucek
PBC International, 1995
Buku Referensi
Forch, Matthias
Springer Nature, 2019
eBooks
Wurm, Jan
Birkhal'user, 2007
Buku Teks
Hutasoit, Andar Parulian
Fakultas Teknik Universitas Indonesia, 1999
UI - Skripsi (Membership)