“PROFESSIONAL DEVELOPMENT OF VOCAL MUSIC TEACHERS IN THE CONTEXT OF LIFELONG LEARNING: THEORETICAL CONNOTATIONS, CORE CHARACTERISTICS AND THEORETICAL FOUNDATIONS ”, iposu, pp. 278–281, Dec. 2025, Accessed: Apr. 05, 2026. [Online]. Available: https://conference.wunu.edu.ua/index.php/iposu/article/view/1197