Cita APA

 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.

Cita MLA

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

Atenció: Aquestes cites poden no estar 100% correctes.