Gatchalian, G.L. and Altoveros, N.C. 2003. Hand-held microcontroller-based instrument for detection of lahars and pyroclastic materials. Proceedings of the Samahang Pisika ng Pilipinas, 21(1), SPP-2003-3A-03. URL: https://proceedings.spp-online.org/article/view/SPP-2003-3A-03.