Black, K. (2014). R object-oriented programming: A practical guide to help you learn and understand the programming techniques necessary to exploit the full power of R. Packt Publishing.

Black, Kelly. R Object-oriented Programming: A Practical Guide to Help You Learn and Understand the Programming Techniques Necessary to Exploit the Full Power of R. Birmingham: Packt Publishing, 2014.

Black, Kelly. R Object-oriented Programming: A Practical Guide to Help You Learn and Understand the Programming Techniques Necessary to Exploit the Full Power of R. Packt Publishing, 2014.