Chen Y, Chen XY, Jakeman LB, Schalk G, Stokes BT, Wolpaw J. The interaction of a new motor skill and an old one: H-reflex conditioning and locomotion in rats. The Journal of neuroscience : the official journal of the Society for Neuroscience [Internet]. 2005;25:6898?6906. http://www.ncbi.nlm.nih.gov/pubmed/16033899