APA (7th ed.) Citation

Thomas, P., Thomas, D., & Everson, W. (2012). The Alder: A poem. Peter & Donna Thomas.

Chicago Style (17th ed.) Citation

Thomas, Peter, Donna Thomas, and William Everson. The Alder: A Poem. Santa Cruz: Peter & Donna Thomas, 2012.

MLA (9th ed.) Citation

Thomas, Peter, et al. The Alder: A Poem. Peter & Donna Thomas, 2012.