*Source of data: Fisher (1936), reproduced by Andrews and Herzberg (1985): Andrews, D. F. and Herzberg, A. M. (1985). Data - A Collection of Problems from Many Fields for the Student and Research Worker. Springer-Verlag, New York.
** Fisher, R. A. (1936). The Use of Multiple Measurements in Taxonomic Problems. Annals of Eugenics 7, Part II. 179-188.