3  Tài liệu tham khảo

Crainiceanu, Ciprian, Brian Caffo, and John Muschelli. 2018. Methods in Biostatistics with R. Leanpub. https://leanpub.com/biostatmethods.

Wickham, Hadley. 2010. “A Layered Grammar of Graphics.” Journal of Computational and Graphical Statistics 19 (1): 3–28. http://book.thuviencanhan.com:8033/results?query=&dir=tuhocr/R+programming/ggplot2/wickham2010&after=&before=&sort=relevancyrating&ascending=0&page=1.