https://dispendik.situbondokab.go.id/berita/ https://vta.kemenhub.go.id/assets/
Suwari, Suwari, Riani, Etty, Pramudya, Bambang, AND Djuwita, Ita. " MODEL DINAMIK PENGENDALIAN PENCEMARAN AIR KALI SURABAYA" Bumi Lestari [Online], Volume 11 Number 2 (1 August 2011)