Data resources : Places where you can download data

UN : http://data.un.org/
US : http://www.data.gov/
http://www.gapminder.org/data/
http://www.asdfree.com/ – with R codes
Kaggle : https://www.kaggle.com/datasets
rOpenSci : https://ropensci.org/

Credit to : https://www.coursera.org/learn/data-cleaning/home/info

AND:

http://data.princeton.edu/wws509/datasets