Please cite R.oo/R.methodsS3 as
Bengtsson H (2003). “The R.oo package - Object-Oriented Programming with References Using Standard R Code.” In Hornik K, Leisch F, Zeileis A (eds.), Proceedings of the 3rd International Workshop on Distributed Statistical Computing (DSC 2003). https://www.r-project.org/conferences/DSC-2003/Proceedings/Bengtsson.pdf.
Corresponding BibTeX entry:
@InProceedings{, author = {Henrik Bengtsson}, title = {The {R.oo} package - Object-Oriented Programming with References Using Standard {R} Code}, booktitle = {Proceedings of the 3rd International Workshop on Distributed Statistical Computing (DSC 2003)}, year = {2003}, editor = {Kurt Hornik and Friedrich Leisch and Achim Zeileis}, address = {Vienna, Austria}, month = {March}, issn = {1609-395X}, url = {https://www.r-project.org/conferences/DSC-2003/Proceedings/Bengtsson.pdf}, howpublished = {https://www.r-project.org/conferences/DSC-2003/Proceedings/}, }