Gaya APA
Guffey, Mary Ellen. (1986).
Business English .
Boston:
Kent Publishing Company.
Gaya Chicago
Guffey, Mary Ellen.
Business English.
Boston:
Kent Publishing Company,
1986.
Tesis.
Gaya MLA
Guffey, Mary Ellen.
Business English.
Boston:
Kent Publishing Company,
1986.
Tesis.
Gaya Turabian
Guffey, Mary Ellen.
Business English.
Boston:
Kent Publishing Company,
1986.
Tesis.