Designing clinical trials for assessing the effects of cognitive training and physical activity interventions on cognitive outcomes: the Seniors Health and Activity Research Program Pilot (SHARP-P) study, a randomized controlled trial. - Legault C; Jennings JM; Katula JA; Dagenbach D; Gaussoin SA; Sink KM; Rapp SR; Rejeski WJ; Shumaker SA; Espeland MA (BMC geriatrics, 2011)