APA (7th ed.) Citation

Guth, H. P., & Schuster, H. E. (1975). American English today: The tools of english. Webster division.

Chicago Style (17th ed.) Citation

Guth, Hans Paul, and Howard Egdar Schuster. American English Today: The Tools of English. New York: Webster division, 1975.

MLA (9th ed.) Citation

Guth, Hans Paul, and Howard Egdar Schuster. American English Today: The Tools of English. Webster division, 1975.