Hooi, Y. C., and H. B. Ahmad. “Optical Kerr Effect in Q-Switched neodymium(lll): Doped Silica Fibre Laser”. Malaysian Journal of Science, vol. 16, no. 2, June 1995, pp. 17-23, http://mjs.um.edu.my/index.php/MJS/article/view/4788.