http://www.nature.com/nnano/journal/v5/n3/abs/nnano.2009.474.html . ^ conventional value of von Klitzing constant , NIST ^ Novoselov, K. S.; et al. (2007). "Room-Temperature Quantum Hall Effect in Graphene" . Science 315 (5817): 1379. doi : 10.1126/science.1137201 . PMID 17303717 . http://arxiv.org/abs/cond-mat/0702408 . Further reading Ando, Tsuneya; Matsumoto, Yukio; Uemura, Yasutada (1975). "Theory of Hall Effect