Sources and Data Sets themself
- RDataMining.com (http://www.rdatamining.com/resources/data)
- UCI machine learning repository (http://archive.ics.uci.edu/ml/)
- KDNuggets (http://www.kdnuggets.com/datasets/index.html)
- Reddit r/datasets (https://www.reddit.com/r/datasets)
- GitHub awesome public datasets (https://github.com/caesar0301/awesome-public-datasets)