D. Cheung, L. Anton, M. Allen, and A. Masters. Abstract Book of the XXIII IUPAP International Conference on Statistical Physics, Genova, Italy, (9-13 July 2007)
M. Feuer, L. Towne, and R. Shavelson. Educational Researcher, 31 (8):
4(2002)“For example, when well-specified causal hypotheses can be formulated and randomization to treatment and control conditions is ethical and feasible, a randomized experiment is the best method for estimating effects” p. 8.