Koehler, Robert, author
Seoul Selection, 2009
Buku Referensi
John, Robert St
Time Incorporated, 1962
Buku Teks
Bocock, Robert
Routledge, 1993
Buku Teks
Cavalier, Robert
Writers and readers Publishing, 1998
Buku Teks
Burns, Robert
Longmans, Green and Co. , 1957
Buku Teks