edited by Ulrich Ammon, Norbert Dittmar, Klaus J. Mattheier
Walter de Gruyter, 1987
Buku Referensi
edited by Ulrich Ammon, Norbert Dittmar, Klaus J. Mattheier
Walter de Gruyter, 1988
Buku Referensi
Fishman, Joshua A., author
Newbury House Publishers, 1972
Buku Teks
Malmstrom, Jean, author
Hayden Book Company, 1965
Buku Teks
Bram, Joseph, author
Random House, 1955
Buku Teks