APA (7th ed.) Citation

Illick, J. S. (1923). Pennsylvania trees. Pennsylvania Dept. of Forestry.

Chicago Style (17th ed.) Citation

Illick, Joseph S. Pennsylvania Trees. [Harrisburg., Pa.]: Pennsylvania Dept. of Forestry, 1923.

MLA (9th ed.) Citation

Illick, Joseph S. Pennsylvania Trees. Pennsylvania Dept. of Forestry, 1923.