“Aplikasi perhitungan tingkat kesuburan perairan dengan Metode Carlson pada perairan urban Danau Polder Air Hitam di Kota Samarinda: Application of Carlson trophic state index on trophic state determination of urban Polder Air Hitam Lake in Samarinda City”, jipt, vol. 2, no. 1, pp. 73–78, Mar. 2023, doi: 10.30872/jipt.v2i1.494.