Orbay, Keziban, and Mehmet Hikmet Develi. “Pre-School students’ Informal Acquisitions Regarding the Concepts of Point and Straight Line”. International Electronic Journal of Elementary Education 7, no. 3 (August 21, 2017): 319–332. Accessed March 1, 2025. https://iejee.com/index.php/IEJEE/article/view/83.