Jindarattanawong J. The Development of a Training Model of Non-Formal Education, Based on Concepts of Constructionism and Self-Directed Learning to Enhance Functional Competencies of Personnel Officers in the Royal Thai Air Force. scho [Internet]. 2014Oct.16 [cited 2024Apr.29];3(1). Available from: http://www.assumptionjournal.au.edu/index.php/Scholar/article/view/279