Received May 30, 2011
Accepted May 30, 2011

Standard references may be classic papers, those based on large data sets or more simply and commonly, the best data set to the present. The latter may be superseded at any time, but the standard must be better. It is incumbent on all practitioners to study the literature and know about the best evidence available. This is continuing education. This paper provides a contemporary list of a number relevant to today’s issues with a brief description of each. They would all repay more detailed study as they set benchmarks for quality.