PT - JOURNAL ARTICLE AU - Ellsworth, Allan TI - Phase IV Drug Studies AID - 10.3122/jabfm.5.1.115 DP - 1992 Jan 01 TA - The Journal of the American Board of Family Practice PG - 115--115 VI - 5 IP - 1 4099 - http://www.jabfm.org/content/5/1/115.short 4100 - http://www.jabfm.org/content/5/1/115.full SO - J Am Board Fam Med1992 Jan 01; 5