1. Clinical Epidemiology: The Architecture of Clinical Research;Feinstein,1985
2. Clinical Trials: Issues and Approaches,1983
3. Scientific challenges in the application of randomized trials;Kramer;JAMA,1984
4. Research in physical medicine and rehabilitation. IV. Some practical designs in applied research;Reilly;Am J Phys Med Rehabil,1989
5. An assessment of research methods reported in 103 scientific articles from two Canadian medical journals;Badgley;Can Med Assoc,1961