APA (7th ed.) Citation

Potter, B., & Morse, J. C. (1982). Beatrix Potter's Americans: Selected letters. Horn Book.

Chicago Style (17th ed.) Citation

Potter, Beatrix, and Jane Crowell Morse. Beatrix Potter's Americans: Selected Letters. Boston, Mass.: Horn Book, 1982.

MLA (9th ed.) Citation

Potter, Beatrix, and Jane Crowell Morse. Beatrix Potter's Americans: Selected Letters. Horn Book, 1982.