He, Lijuan     Survey on the Status of the Elderly Male Population in Participating Physical Exercises in Beijing [Текст] / Lijuan He, Wei. Liu // Olympic sport and sport for all : proceedings of 17th International scientific congress ( Beijing, China, 2nd-6th, June, 2013) / International Association of Universities of Physical Culture and Sport, Capital University of Physical Education and Sports. — Beijing, 2013. — P. 113.