References
- Bickel , P. J. and Doksum , K. A. 1977 . Mathematical Statistics: Basic Ideas and Selected Topics , San Francisco : Holden-Day .
- Lehmann , E. L. 1975 . Nonparametrics: Statistical Methods Based on Ranks , New York : John Wiley .
- Randles , R. H. and Wolfe , D. A. 1979 . Introduction to the Theory of Nonparametric Statistics , New York : John Wiley .