edited by Geoffrey A. Hosking and George F. Cushing
Macmillan Press, 1989
Buku Teks SO
Charles Webel and Mark Tomass, editors
Routledge, Taylor & Francis Group, 2017
Buku Teks
edited by Walter K. Gordon
Appleton-Century-Crofts, 1968
Buku Teks SO
Burton, Graeme
McGraw-Hill, 2010
Buku Teks SO
Hall, James
John murray, 1995
Buku Referensi