References/Notes/Attributions:
Source
The data were obtained from
Frets, G.P. (1921) Heredity of head form in man. Genetica, 3, 193.
References
Davison, A.C. and Hinkley, D.V. (1997) Bootstrap Methods and Their Application. Cambridge University Press.
Whittaker, J. (1990) Graphical Models in Applied Multivariate Statistics. John Wiley.