1. History ofpharmacy;Kremers, E.; Urdang, G.,1976
2. Statistics: the problem of examining accumulating data more than once;McPherson, K.;N EnglJ Med,1979
3. Interim analyses and stopping rules for clinical trials;Pocock, S.J.,1981
4. Primary, secondary and meta-analysis of research;Glass, G.V.;Educational Research,1976
5. Meta-analyses of randomised controlled trials;Sacks, H.S.; Berrier, J.; Reitman, D.;N EnglJ Med,1987