1. The importance of beta, the type II error and sample size in the design and interpretation of the randomized control trial: survey of 71 “negative” trials;Freiman;N Engl J Med,1978
2. Statistical power, sample size, and their reporting in randomized controlled trials;Moher;JAMA,1994
3. Low power, type II errors, and other statistical problems in recent cardiovascular research;Williams;Am J Physiol,1997
4. Type-II error rates (beta errors) of randomized trials in orthopaedic trauma;Lochner;J Bone Joint Surg Am,2001
5. The power of tests to detect differences between periodontal treatments in published studies;Hujoel;J Clin Periodontol,1992