Konopasek, Roger, author
Gramedia Pustaka Utama, 2004
Buku Teks
Sales, Roger
Routledge, 1997
Buku Teks
Green, Roger Lancelyn
New York Oxford 1998,
Buku Teks
Neimark, Edith D., author
Harcourt Brace Javanovich, 1987
Buku Teks
Whitehead, Alfred North, 1861-1947, author
The New American Library, 1933
Buku Teks