Cita APA (7th ed.)

(1992). Webster's 21st century: Complete guide to speech, style and grammar. T. Nelson.

Cita Chicago (17th ed.)

Webster's 21st Century: Complete Guide to Speech, Style and Grammar. Nashville: T. Nelson, 1992.

Cita MLA (9th ed.)

Webster's 21st Century: Complete Guide to Speech, Style and Grammar. T. Nelson, 1992.