Mahmood, A. I., A. I. Mahmood, and S. S. Ahmed. “Refractive Index Sensor Based on Micro- Structured Optical Fibers With Using Finite Element Method”. Iraqi Journal of Science, Vol. 59, no. 3C, Sept. 2018, pp. 1577-86, https://ijs.uobaghdad.edu.iq/index.php/eijs/article/view/385.