1. Variations of posture and behaviour of the lips and tongue which determine the position of the labial segments; the implications in orthodontics, prosthetics, and speech;Ballard;Trans. Eur. Orthod. Soc.,1963
2. Radiographic study of oral structures and their relation to anterior tooth position;Ellinger;J. Prosthet. Dent.,1968
3. Principles of Full Denture Prosthesis;Fish,1948
4. Functional factors in the selection and arrangement of artificial teeth;Hooper;J. Am. Dent. Assoc.,1934
5. Changes in soft-tissue profile following extraction and complete denture treatment;Ismail;J. Prosthet. Dent.,1971