APA

Hickman G. C., Hickman S. M., . (2002). The ecology action guide. San Francisco, California: Pearson Education.

Chicago

Hickman Graham C, Hickman Susan M, . 2002. The ecology action guide. San Francisco, California: Pearson Education.

Harvard

Hickman G. C., Hickman S. M., . (2002). The ecology action guide. San Francisco, California: Pearson Education.

MLA

Hickman Graham C, Hickman Susan M, . The ecology action guide. San Francisco, California: Pearson Education. 2002.