TY - JOUR T1 - On the Nature and Analysis of Clustered Data JF - The Annals of Family Medicine JO - Ann Fam Med SP - 199 LP - 200 DO - 10.1370/afm.197 VL - 2 IS - 3 AU - Stephen J. Zyzanski AU - Susan A. Flocke AU - L. Miriam Dickinson Y1 - 2004/05/01 UR - http://www.annfammed.org/content/2/3/199.abstract N2 - ER -