Gaya APA

Hickman, M., Wigginton, E, O. (2009). Coorperative problem-solving activities for social studies: grades 6-12 . United States of America: Corwin Sage.

Gaya MLA

Hickman, Michael., Wigginton, Erin, O'Donnell. "Coorperative problem-solving activities for social studies: grades 6-12". United States of America: Corwin Sage, 2009. Text.