APA (7th ed.) Citation

Philbrick, H., & Gregg, R. B. (2016). Companion and how plants to use them. Floris Books.

Chicago Style (17th ed.) Citation

Philbrick, Helen, and Richard B. Gregg. Companion and How Plants to Use Them. Great Britain: Floris Books, 2016.

MLA (9th ed.) Citation

Philbrick, Helen, and Richard B. Gregg. Companion and How Plants to Use Them. Floris Books, 2016.