McFarland DJ. A single g factor is not necessary to simulate positive correlations between cognitive tests. J Clin Exp Neuropsychol [Internet]. 2012;34(4):378-84. http://www.ncbi.nlm.nih.gov/pubmed/22260190

Schalk G, McFarland DJ, Hinterberger T, Birbaumer N, Wolpaw J. BCI2000: a general-purpose brain-computer interface (BCI) system. IEEE Trans Biomed Eng. 2004;51(6):1034-43.