Roze, Maris
Prentice-Hall, 2002
Buku Teks SO
Springer Nature Singapore, 2019
eBooks
Novianti Suhendar Putri
Fakultas Ilmu Pengetahuan Budaya Universitas Indonesia, 2007
UI - Skripsi Membership
Aitchison, Jean, 1938-
Hodder & Stoughton, 1992
Buku Teks SO
edited by Archibald A. Hill
Voice of America, 1969
Buku Teks