Cita APA (7th ed.)

Regents pub. co. (1977). The Blue book of business English. Regent Pub.

Cita Chicago (17th ed.)

Regents pub. co. The Blue Book of Business English. New york: Regent Pub, 1977.

Cita MLA (9th ed.)

Regents pub. co. The Blue Book of Business English. Regent Pub, 1977.