APA (7th ed.) Citation

Riddlesbarger, A., Cotner, E. P., & Beveridge, J. H. (1926). Easy English exercises. World Book Co..

Chicago Style (17th ed.) Citation

Riddlesbarger, Ada, Edna Parker Cotner, and John Harrie Beveridge. Easy English Exercises. Yonkers-on-Hudson, N.Y. ; Chicago: World Book Co., 1926.

MLA (8th ed.) Citation

Riddlesbarger, Ada, et al. Easy English Exercises. World Book Co., 1926.