Periodicals>Journal Article:  Chekroud, Gueorguieva, Zheutlin, Paulus, Krumholz, Krystal, Chekroud (August 08, 2018), Association between physical exercise and mental health in 1·2 million individuals in the USA between 2011 and 2015: a cross-sectional study, The Lancet, Retrieved on 2018-10-31

Source Material [www.thelancet.com]