1. Arnim, S. S. Personal communication.
2. The use of disclosing agents for measuring tooth cleanliness;Arnim;J. Periodont.,1963
3. Barkley, R. F. Personal communication.
4. Swab test for dental caries activity: An epidemiological study;Grainger;J.C.D.A.,1965
5. Modern Dental Practice: Concepts and Procedures;Hollander,1967