Hidayat, Rifki, Cut Nawalul Azka, Aldina Fatimah, and Teuku Andrian Firmansyah. “Subgrade Optimization With Coconut Shell Ash Addition on Glee Gurah Clay Soil”. Jurnal Komposit: Jurnal Ilmu-ilmu Teknik Sipil 9, no. 2 (August 5, 2025): 393–402. Accessed December 16, 2025. http://150.107.142.43/index.php/komposit/article/view/19087.