MLA

Thorn, Alan, and Marc Schärer. Learn Unity for 2d Game Development. Apress, 2013.

APA

Thorn, A., & Schärer, M. (2013). Learn Unity for 2D Game Development. Apress.

Chicago

Thorn, Alan, Marc Schärer, and Marc Schärer. Learn Unity for 2D Game Development. : Apress, 2013.