Robertson, Priscilla
University Press, 1971
Buku Teks SO
Rida Zuraida
Faculty of Engineering, Universitas Indonesia, 2017
Artikel Jurnal
Ingleson, John
Hineman Educational Books, 1979
Buku Teks SO
Mccarthy, Cormac
Vintage International, 2006
Buku Teks SO
Peretz, Don
Westview press, 1990
Buku Teks SO