PT - JOURNAL ARTICLE AU - E. A. Carr, Jr TI - Practical considerations in the design of clinical trials DP - 1968 Feb 10 TA - Canadian Medical Association Journal PG - 307--313 VI - 98 IP - 6 4099 - http://www.cmaj.ca/content/98/6/307.short 4100 - http://www.cmaj.ca/content/98/6/307.full SO - CMAJ1968 Feb 10; 98