Supavititpatana, Bungorn, Kobkul Phancharoenworakul, Soen Ae Yeo, Nittaya Sinsuksai, and Thavatchai Vorapongsathorn. 2013. “Using Theory of Planned Behavior to Predict Physical Activity Intention Among Pregnant Thais”. Pacific Rim International Journal of Nursing Research 16 (3):192-205. https://he02.tci-thaijo.org/index.php/PRIJNR/article/view/5864.