APA (7th ed.) Citation

Philbrick, H., & Gregg, R. B. (1991). Companion plants: Plants that help each other and how to use them (Rev. ed.). Kangaroo Press.

Chicago Style (17th ed.) Citation

Philbrick, Helen, and Richard B. Gregg. Companion Plants: Plants That Help Each Other and How to Use Them. Rev. ed. [Australia]: Kangaroo Press, 1991.

MLA (9th ed.) Citation

Philbrick, Helen, and Richard B. Gregg. Companion Plants: Plants That Help Each Other and How to Use Them. Rev. ed. Kangaroo Press, 1991.

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