1. Ajzen, I. (n.d.-a). Constructing a Theory of Planned Behavior Questionnaire. Retrieved from: http://people.umass.edu/aizen/pdf/tpb.measurement.pdf
2. Ajzen, I. (n.d.-b). Sample TPB Questionnaire. Retrieved from: http://people.umass.edu/aizen/pdf/tpb.questionnaire.pdf
3. From intentions to actions: A theory of planned behavior;Ajzen,1985
4. The theory of planned behavior;Ajzen;Organizational Behavior and Human Decision Processes,1991
5. Ajzen, I. (2006). Theory of planned behavior. Retrieved from: http://people.umass.edu/aizen/tpb.diag.html