Whibley D, AlKandari N, Kristensen K, Barnish M, Rzewuska M, Druce KL, Tang NKY. Sleep and pain: a systematic review of studies of mediation. Clin JPain. 2019 Jun;35(6):544-58. doi: 10.1097/AJP.0000000000000697
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.