Bogdan Draganski, Christian Gaser, Volker Busch, Gerhard Schuierer, Ulrich Bogdahn, and Arne May, «Neuroplasticity: Changes in Grey Matter Induced by Training», Nature 427, no. 6972 (2004): 311–12; Arne May, Gören Hajak, S. Gänssbauer, Thomas Steffens, Berthold Langguth, Tobias Kleinjung, and Peter Eichhammer, «Structural Brain Alterations Following 5 Days of Intervention: Dynamic Aspects of Neuroplasticity», Cerebral Cortex 17, no. 1 (2007): 205–10.