Jörg’s PhD book Data Mining und Graph Mining auf molekularen Graphen - Chemoinformatik und molekulare Kodierungen für ADME/Tox-QSAR-Analysen has a dump of the JavaDoc of the GroupContributionPredictor in JOELib (Figure 3.2, page 43). There are two nice things to the shown JavaDoc: 1. it has links to Wikipedia; 2. it has a Further Reading section. Now, the CDK already links to a bibliography for some time now.