TY - JOUR A1 - Graham, J.W. A1 - Olchowski, A.E. A1 - Gilreath, T.D. T1 - How many imputations are really needed? Some practical clarifications of multiple imputation theory Y1 - 2007 DO - 10.1007/s11121-007-0070-9 JF - Prevention Science VL - 8 IS - 3 SP - 206 EP - -213 ER -