Self-setting of physical activity goals and effects on perceived difficulty, importance and competence.

Privender Saini Joyca Lacroix Self-setting of physical activity goals and effects on perceived difficulty, importance and competence. 33 2009 PERSUASIVE http://doi.acm.org/10.1145/1541948.1541992 conf/persuasive/2009 db/conf/persuasive/persuasive2009.html#SainiL09