Gatens, Moira
Routledge, taylor & francis group, 1999
Buku Teks
de Vries, Theun, author
EM. Querido's Uitgeverij B.V, 1985
Buku Teks
Philosophical Library , 1951
Buku Teks
Morton, Adam, author
Polity Press, 2013
Buku Teks
Casey, Edward S., 1939-, author
Spring Publications, 1991
Buku Teks