APA (7th ed.) Citation

Northen, H., & Northen, R. T. (1954). The secret of the green thumb. Ronald Press Co..

Chicago Style (17th ed.) Citation

Northen, Henry, and Rebecca Tyson Northen. The Secret of the Green Thumb. New York: Ronald Press Co., 1954.

MLA (9th ed.) Citation

Northen, Henry, and Rebecca Tyson Northen. The Secret of the Green Thumb. Ronald Press Co., 1954.

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