References
Matloff, Norman. 2011. The Art of R Programming.
Wickham, Hadey. 2014. “Tidy Data.” The Journal of Statistical Software 59 (10). http://www.jstatsoft.org/v59/i10/.
Wilkinson, Leland. 2005. The Grammar of Graphics.
Matloff, Norman. 2011. The Art of R Programming.
Wickham, Hadey. 2014. “Tidy Data.” The Journal of Statistical Software 59 (10). http://www.jstatsoft.org/v59/i10/.
Wilkinson, Leland. 2005. The Grammar of Graphics.