SRICHIANGSA, W.; ART-IN , S. THE DEVELOPMENT OF ENGLISH SPEAKING ABILITY USING FLIPPED CLASSROOM WITH DUOLINGO FOR FIRST-YEAR VOCATIONAL CERTIFICATE STUDENTS. Academic Journal Phranakhon Rajabhat University, [S. l.], v. 17, n. 1, p. 47–61, 2026. Disponível em: https://so01.tci-thaijo.org/index.php/AJPU/article/view/285560. Acesso em: 16 sep. 2026.