A. Wilper, C. Smith, and W. Weppner. Medical Education Online, (2013-9-16)PMCID: PMC3776321 ; Lizenzbedingungen: open-access http://creativecommons.org/licenses/by/2.0/: This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. ; Quelldatenbank: PUBMED.