* [http://article.gmane.org/gmane.science.nmr.relax.scm/17615 The M61 model]
* [http://article.gmane.org/gmane.science.nmr.relax.scm/17729 The M61 skew model]
* [http://article.gmane.org/gmane.science.nmr.relax.scm/17756 The DPL94 model]
=== The target function ===