edited by Robert O. Freedman
Westview Press, 1984
Buku Teks SO
Harari, Maurice
Prentice-Hall, 1962
Buku Teks
Palmer, Monte
Thomson Wadsworth, 2007
Buku Teks SO
Andersen, Roy R.
Pearson/Prentice Hall, 2007
Buku Teks
Andersen, Roy R.
Longman, 2012
Buku Teks SO