Tilukay, Meilin, and Venn Ilwaru. 2015. “THE ENTIRE FACE IRREGULARITY STRENGTH OF A BOOK WITH POLYGONAL PAGES”. BAREKENG: Jurnal Ilmu Matematika Dan Terapan 9 (2), 103-8. https://doi.org/10.30598/barekengvol9iss2pp103-108.