The data was originally published by Chitty et al., 1993, and analysed in
Royston and Altman, 1994 (the data is given there). Only measurments with
age <= 28<="" code=""> were used in this analysis.
References
L. S. Chitty and S. Campbell and D. G. Altman (1993),
Measurement of the fetal mandible -- feasibility and
construction of a centile chart., Prenatal Diagnosis,
13, 749--756.
P. Royston and D. G. Altman (1994), Regression Using
Fractional Polynomials of Continuous Covariates: Parsimonious
Parametric Modelling. Applied Statistics, 43, 429--453.