Try *Hahn and Shapiro* **Statistical Models in Engineering** and the discussion of the *Pearson Distribution*. This is illustrated within [Wikipedia][1] and relationships to well-known distributions are shown in section 4 of the same page. You can also find more background information [here][2]. [1]: https://en.wikipedia.org/wiki/Pearson_distribution [2]: http://stats.stackexchange.com/questions/46889/peakedness-of-a-skewed-probability-density-function/73183#73183