Volunteerism and self-selection bias in human positron emission tomography neuroimaging research
Brain Imaging and Behavior (2013) - Comment
pubmed: 23196924  doi: 10.1007/s11682-012-9210-3  issn: 1931-7565  issn: 1931-7557 

Lynn M. Oswald, Gary S. Wand, Shijun Zhu, Victoria Selby