Ponseca, C.S., Estacio, E., Murakami, H., Sarukura, N., Pobre, R., Nishizawa, J.- ichi, Suto, K., Sasaki, T., Tanno, T. and Tominaga, K. 2007. Intra- and inter-molecular interaction of 9-cis and all-trans retinal isomers in the 0.45 to 5.5 terahertz region . Proceedings of the Samahang Pisika ng Pilipinas, 25(1), SPP-2007-2B-04. URL: https://proceedings.spp-online.org/article/view/SPP-2007-2B-04.