An age-tailored intervention sustains physical activity changes in older adults: a randomized controlled trial
International Journal of Behavioral Medicine (2014) - Comment
pubmed: 23860624  doi: 10.1007/s12529-013-9330-1  issn: 1070-5503  issn: 1532-7558 

Paul Gellert, Jochen P. Ziegelmann, Simon Krupka, Nina Knoll, Ralf Schwarzer