To cite 'units' in publications use:
Pebesma E, Mailund T, Hiebert J (2016). “Measurement Units in R.” R Journal, 8(2), 486–494. doi: 10.32614/RJ-2016-061.
Corresponding BibTeX entry:
@Article{, title = {Measurement Units in {R}}, author = {Edzer Pebesma and Thomas Mailund and James Hiebert}, year = {2016}, journal = {R Journal}, doi = {10.32614/RJ-2016-061}, pages = {486--494}, volume = {8}, number = {2}, }