Jessup, Ronald
Macdonald, 1968
Buku Teks SO
Christian Baumgartner , Martin Uitz, Karl Krainer, Peter Hasslacher
The Federal Press Service, 2002
Buku Referensi
Buku Teks
edited by Don Rubin, Peter Nagy and Philippe Rouyer
Routledge, 2001
Buku Referensi
edited by Daniel Meyer-Dingrafe
Routledge, 2000
Buku Referensi