Mateo, D., Rodrigo, P.J., Daria, V.R. and Saloma, C. 1998. Crossing-based optical spectrum analyzer. Proceedings of the Samahang Pisika ng Pilipinas, 16(1), SPP-1998-IC-09. URL: https://proceedings.spp-online.org/article/view/SPP-1998-IC-09.