Kelly, Michelle E., Duff, Hollie, Kelly, Sara, McHugh Power, Joanna E., Brennan, Sabina, Lawlor, Brian A. and Loughrey, David G. (2017) The impact of social activities, social networks, social support and social relationships on the cognitive functioning of healthy older adults: a systematic review. Systematic Reviews, 6 (259). ISSN 2046-4053