APA (7th ed.) Citation

Shigo, A. L. (1983). Tree defects: A photo guide. U.S. Dept. of Agriculture, Forest Service, Northeastern Forest Experiment Station.

Chicago Style (17th ed.) Citation

Shigo, Alex L. Tree Defects: A Photo Guide. Broomall, Pa.: U.S. Dept. of Agriculture, Forest Service, Northeastern Forest Experiment Station, 1983.

MLA (9th ed.) Citation

Shigo, Alex L. Tree Defects: A Photo Guide. U.S. Dept. of Agriculture, Forest Service, Northeastern Forest Experiment Station, 1983.