1. Ball C, Sackett D, Phillips R, et al: Levels of evidence and grades of recommendations. http://cebm.jr2.ox.ac.uk/docs/levels.html. (last update 9/17/98; date accessed 7/31/99)
2. Ruling out the diagnosis [edit];Bigby;Arch Dermatol,1996
3. Evidence-based medicine in a nutshell: A guide to finding and using the best evidence in caring for patients;Bigby;Arch Dermatol,1998
4. Understanding and evaluating clinical trials;Bigby;J Am Acad Dermatol,1996
5. An evaluation of method reporting and use in clinical trials in dermatology;Bigby;Arch Dermatol,1985