Not only EMF epidemiological studies are controversial for lack of standards. See the review of 56 areas with contradictory epidemiological data where the authors concluded "We suggest that much of the disagreement may occur because a set of rigorous scientific principles has not yet been accepted to guide the design or interpretation of case-control research." (L.C. Mayes, R.I. Horwitz and A.R. Feinstein: A collection of 56 topics with contradictory results in case-control research, Int. J. Epidemiol. 17:680-685, 1988.)