Xu J, Evans J, Coon C, Copley-Merriman K, Su Y. Measuring patient-reported outcomes in advanced gastric cancer. Ecancermedicalscience. 2013;7:351. doi: 10.3332/ecancer.2013.351.
Hartman M, Bolton E, Fehnel SE. Accounting for age differences on the Wisconsin Card Sorting Test: decreased working memory, not inflexibility. Psychol Aging. 2001 Sep 1;16(3):385-99.