ORBAY, Keziban; DEVELI, Mehmet Hikmet. Pre-school students’ informal acquisitions regarding the concepts of point and straight line. International Electronic Journal of Elementary Education, [S. l.], v. 7, n. 3, p. 319–332, 2017. Disponível em: https://www.iejee.com/index.php/IEJEE/article/view/83. Acesso em: 4 aug. 2026.