1. Progressive relaxation: A manual for therapist;Bernstein,1973
2. Back to basics: Percentage agreement measures are adequate, but there are easier ways;Birkimer;Journal of Applied Behavior Analysis,1979
3. Critical procedural variables related to the physiological effects of progressive relaxation: A review;Borkovec;Behaviour Research and Therapy,1979
4. Relaxation: A comprehensive manual for adults, children, and children with special needs;Cautela,1978
5. Applied multiple regression/correlation analysis for the behavioral sciences;Cohen,1975