Heijbroek, A.M.A., author
Rabobank International Group, [Date of publication not identified]
Buku Teks
Davis, Jack, author
Currency, 1986
Buku Teks
Jolley, Elizabeth, author
Fremantle Arts Centre Press, 1988
Buku Teks
Chen, James C. P., author
Wiley, 1985
Buku Referensi
Marianne Wait, editor
Reader's Digest, 2007
Buku Teks