Aldine Publishing Company, 1964
Buku Teks SO
New Delhi, India : Indian Council for Cultural Relation
Majalah, Jurnal, Buletin
Simpson, W.O.
Stanley Thornes, 1986
Buku Teks SO
edited by Gerald W. Whitted
Pan American World Airways, 1971
Buku Referensi
Institute of Humanities, Seoul National University,
Majalah, Jurnal, Buletin