Spaemann, Robert
Routledge, 1991
Buku Teks
Long, Edward LeRoy
Oxford University Press , 1967
Buku Teks
Thiroux, Jacques P. author
Pearson, 2015
Buku Teks
Merton, Robert K., author
Harcourt Brace Jovanovich, 1976
Buku Teks
Altman, Matthew C, author
John Wiley & Sons, 2014
Buku Teks