Hartman, J. R., Pirone, T. P., & Sall, M. A. (2000). Pirone's tree maintenance (7th ed.). Oxford University Press.

Hartman, John Richard, T. P. Pirone, and Mary Ann Sall. Pirone's Tree Maintenance. 7th ed. Oxford ; New York: Oxford University Press, 2000.

Hartman, John Richard, et al. Pirone's Tree Maintenance. 7th ed. Oxford University Press, 2000.