C. Larino, R. ., & M. Castañares, J. . (2019). The Effect of Pulang-Bato Spring on the Levels of Copper and Zinc at the Zone of Impact of the Spring and a Section of Butuanon River. International Journal of Sciences: Basic and Applied Research (IJSBAR), 48(6), 82–107. Retrieved from https://gssrr.org/index.php/JournalOfBasicAndApplied/article/view/10337