Prihandika, Aditya, and Krisna Satrio Perbowo. “The Review of Concept Image and Concept Definition: A Hermeneutic Phenomenological Study on the Derivative Concepts”. International Journal of Didactic Mathematics in Distance Education, vol. 1, no. 1, Apr. 2024, pp. 13-23, http://jurnal.ut.ac.id/index.php/ijdmde/article/view/7610.