APA (7th ed.) Citation

Merriam-Webster, Inc. (1989). Webster's dictionary of english usage. Merriam-Webster.

Chicago Style (17th ed.) Citation

Merriam-Webster, Inc. Webster's Dictionary of English Usage. Springfield, Mass: Merriam-Webster, 1989.

MLA (9th ed.) Citation

Merriam-Webster, Inc. Webster's Dictionary of English Usage. Merriam-Webster, 1989.

Warning: These citations may not always be 100% accurate.