format
A list providing a summary of the data. The list contains:
lcl{
pubprod$means : the mean vector,
pubprod$stddev : the vector of standard deviations,
pubprod$corr : the correlation matrix, and
pubprod$n : the sample size.
}source
Spirtes, P., Glymour, C. & Scheines, R. (2000) Causation,
Prediction, and Search. Cambridge, Massachusetts: The MIT
Press. (See Example 5.8.1).