APA (7th ed.) Citation
(1994). Project learning tree: Environmental education activity guide (2nd.). Project Learning Tree.
Chicago Style (17th ed.) Citation
Project Learning Tree: Environmental Education Activity Guide. 2nd. Washington: Project Learning Tree, 1994.
MLA (9th ed.) Citation
Project Learning Tree: Environmental Education Activity Guide. 2nd. Project Learning Tree, 1994.
Warning: These citations may not always be 100% accurate.