widada, wahyu. 2015. “THE EXISTENCE OF STUDENTS IN TRANS EXTENDED COGNITIVE DEVELOPMENT ON LEARNING OF GRAPH THEORY*)”. Jurnal Math Educator Nusantara: Wahana Publikasi Karya Tulis Ilmiah Di Bidang Pendidikan Matematika 1 (1). https://doi.org/10.29407/jmen.v1i1.119.