Everitt and Dunn (2001) obtained the data from Manly, B. F. J. 1986. Multivariate Statistical Methods: A Primer. London: Chapman & Hall.
Source: Data obtained from table 11.5, page 269 of Everitt, B. S., and G. Dunn. 2001. Applied Multivariate Data Analysis. 2nd ed. London: Arnold.