KAUR, D. P. A Study of The Effects of Classroom Structure and Instructional Methods on Students Learning of Trigonometric Concepts in Mathematics. European Economic Letters (EEL), [S. l.], v. 13, n. 5, p. 1421–1428, 2023. DOI: 10.52783/eel.v13i5.923. Disponível em: https://www.eelet.org.uk/index.php/journal/article/view/923. Acesso em: 10 oct. 2025.