Rahma Wati, Y., Herawati, H., Akbarsyah, N. and Zahidah 2025. Primary Productivity Based on Chlorophyll-a Concentration in the Luk Ulo River Estuary, Kebumen Regency, Central Java . Grouper. 16, 2 (Sep. 2025), 357–367. DOI:https://doi.org/10.30736/grouper.v16i2.325.