1. L. Hu and W. Zhang, Computer-Aided Design 127, 102885 (2020).
2. M. I. E. Zulkifly, A. F. Wahab, and R. Zakaria, IAENG Journal of Applied Mathematics 50, (2020).
3. N. A. A Karim, A. F. Wahab, R. U. Gobithaasan, and R. Zakaria, Far East Journal of Mathematical Sciences 72, 269–280 (2013).
4. M. Zamani, Contemporary Engineering Sciences 2, (2009).
5. A. F. Wahab, “Pemodelan Geometri Menggunakan Teori Set Kabur [Geometric Modelling using Fuzzy SetTheory],” Ph.D. thesis, Universiti Sains Malaysia 2008.