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    ".. [1]  https://www.itl.nist.gov/div898/handbook/eda/section3/eda357.htm",
    ".. [2]  Snedecor, George W. and Cochran, William G. (1989), Statistical",
    "          Methods, Eighth Edition, Iowa State University Press.",
    ".. [3] Park, C. and Lindsay, B. G. (1999). Robust Scale Estimation and",
    "       Hypothesis Testing based on Quadratic Inference Function. Technical",
    "       Report #99-03, Center for Likelihood Studies, Pennsylvania State",
    "       University.",
    ".. [4] Bartlett, M. S. (1937). Properties of Sufficiency and Statistical",
    "       Tests. Proceedings of the Royal Society of London. Series A,",
    "       Mathematical and Physical Sciences, Vol. 160, No.901, pp. 268-282."
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