Cottrell, Robert, author
John Murray , 1993
Buku Teks
Moffitt, Ian, author
Collins, 1982
Buku Teks
Nicolson, Harold, author
Oxford, 1969
Buku Teks
Kissinger, Henry, 1923-, author
Schuter, 1994
Buku Teks
Hicks, George L., author
Ubiters' & Publishers, 1989
Buku Teks