Physical and social activities mediate the associations between social network types and ventilatory function in Chinese older adults
Health Psychology (2014) - Comment
pubmed: 24884906  doi: 10.1037/hea0000026  issn: 1930-7810  issn: 0278-6133 

Sheung-Tak Cheng, Edward M. F. Leung, Trista Wai Sze Chan