Locke, John
Routledge, 2000
Buku Referensi
Locke, John
Hackett Publishing Company, Inc., 1996
Buku Teks SO
Banerjee, Nikunja Vihari
George Allen and Unwin, 1958
Buku Teks SO
Hume, David
J.M. Dent & Sons , 1959
Buku Teks SO
Locke, John
J.M. Dent & Sons, 1947
Buku Teks SO