Ruiling, Han, and Shafizan Bin Sabri. 2025. “Development and Validation of A Survey for Measuring Instructors’ Pedagogical Content Knowledge Level of One-To-One Pop Singing Courses at the Conservatories in China”. International Journal of Academic Research in Progressive Education and Development 14 (1):43-53. https://www.ijarped.com/index.php/journal/article/view/3319.