APA Citation

 Thorpe, G. S. (2007).  AP environmental science.  Barron’s Educational Series.

Chicago Style Citation

 Thorpe, Gary S.  AP Environmental Science.  Barron’s Educational Series, 2007.

MLA Citation

 Thorpe, Gary S.  AP Environmental Science.  Barron’s Educational Series, 2007.

Warning: These citations may not always be 100% accurate.