Journal of Statistical Software: 2013, vol: 54, issue: 10
1)- Sarah M Kreidler, Keith E Muller, Gary K Grunwald, Brandy M Ringham, Zacchary T Coker-Dukowitz, Uttara R Sakhadeo, Anna E BarĂ³n, Deborah H Glueck. : Online Power Computation for Linear Models with and without a Baseline Covariate.Journal of statistical software. 2013, 54 (10):