@book{siegel:b88, author = {Siegel, S. and Castellan, N.J.}, edition = {Second}, interhash = {a7aa17712ec15867d7803811e5267a88}, intrahash = {e2ac0dc902159ea0b174e65a72cb40e0}, publisher = {McGraw--Hill, Inc.}, title = {Nonparametric statistics for the behavioral sciences}, year = 1988 }