Dummett, Michael
Duckworth , 1993
Buku Teks
Kaplan, Jeffrey P., author
Prentice Hall International, 1995
Buku Teks
Jespersen, Otto, author
George Allen and Unwin, 1933
Buku Teks
Makkink, H.J., author
Nijgh and Van Ditmar, 1951
Buku Teks
House, C. Homer, author
Prentice-Hall, 1950
Buku Teks