1. Textbook of radiographic positioning and related anatomy;Bontrager,2010
2. Radiographic technique and image evaluation;Unett,2001
3. Clark’s positioning in radiography;Whitley,2005
4. Department of Health;Ionizing Radiation (Medical Exposure) Regulations,2000
5. A randomised control trial comparing lateral skull computerised radiographs with or without a grid;Bartholomew;Radiography,2004