Pieper, Josef, author
Pantheon Books, 1955
Buku Teks
edited by Milton Fisk
Humanities Press, 1993
Buku Teks
edited by Don M. Gottfredson, Ronald V. Clarke
Aldershot Avebury , 1990
Buku Teks
Robinson, Darryl, author
Cambridge University Press, 2020
eBooks
Artikel Jurnal