External Links:
Blog post on how to use the terminal in RStudio:
http://students.brown.edu/seeing-theory/
http://www-bcf.usc.edu/~gareth/ISL/
http://r4ds.had.co.nz/
https://www.rstudio.com/resources/cheatsheets/
http://datavizproject.com/
https://www.gabrielaplucinska.com/
http://colorbrewer2.org/