Gaya APA

Gravells, A. (2009). Principles and Practice of Assesment in the Lifelong Learning Sector . Glasgow: Bell and Bain Ltd.

Gaya MLA

Gravells, Ann. "Principles and Practice of Assesment in the Lifelong Learning Sector". Glasgow: Bell and Bain Ltd, 2009. Buku PPS Pend. Biologi.