Magalhães, C., Teixeira, C., Teixeira, R., Machado, A., Azevedo, I., & Bordalo, A. (2008). Dissolved organic carbon and nitrogen dynamics in the Douro River estuary, Portugal. Ciencias Marinas, 34(3), 271–282. https://doi.org/10.7773/cm.v34i3.1393