APA (7th ed.) Citation

DeMars, D. J., & Barrett, J. W. (1987). Ponderosa pine managed-yield simulator: PPSIM users guide. U.S. Dept. of Agriculture, Forest Service, Pacific Northwest Research Station.

Chicago Style (17th ed.) Citation

DeMars, Donald J., and James W. Barrett. Ponderosa Pine Managed-yield Simulator: PPSIM Users Guide. Portland, Or.: U.S. Dept. of Agriculture, Forest Service, Pacific Northwest Research Station, 1987.

MLA (9th ed.) Citation

DeMars, Donald J., and James W. Barrett. Ponderosa Pine Managed-yield Simulator: PPSIM Users Guide. U.S. Dept. of Agriculture, Forest Service, Pacific Northwest Research Station, 1987.