Physical activity derived from questionnaires and wrist-worn accelerometers: comparability and the role of demographic, lifestyle, and health factors among a population-based sample of older adults

Author(s)	Koolhaas C M, van Rooij F J, Cepeda M, Tiemeier H, Franco O H, Schoufour J D
Journal / Source	https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5739112/pdf/clep-10-001.pdf
Date	January 2018