By Session

It was an article of J. Friedel in The Physics of Metals, ed. by J. Ziman in 1969, which strongly affected my thinking about electronic correlations. It was so clearly written, that it was obvious how to generalize the work of Gutzwiller. In the meantime, the subject has tremendously developed. Recent progress will be discussed on electronic structure calculations for strongly correlated electron systems based on many-body wavefunctions.