G & C Merriam Co., 1947
Buku Referensi
Martin, E. A. (Elizabeth A.)
MacMillan Press, 1985
Buku Referensi
Lawrence, Eleanor
John Wiley & Sons, 1989
Buku Teks
general editor, David W. Pearce
Macmillan Reference Books, 1989
Buku Referensi
general editor, David W. Pearce
Macmillan Press, 1992
Buku Referensi