Remoto, R.J., Pobre, R.F. and Edmiston, M.F. 2005. Chlorophyll-a fluorescence analysis of ipil (Intsia bijuga) leaves under different biofertilizer treatments. Proceedings of the Samahang Pisika ng Pilipinas, 23(1), SPP-2005-PA-06. URL: https://proceedings.spp-online.org/article/view/SPP-2005-PA-06.