Ratnanik, Ratnanik, et al. “KAJIAN OPTIMALISASI DISTRIBUSI JARINGAN AIR BERSIH (STUDI KASUS PDAM DELTA TIRTA SIDOARJO UNIT IPA KRIAN): Study on Water Distribution Network Optimization (A Case Study in the Sidoarjo Drinking Water Company of the Subdistric of Krian)”. Spektrum Sipil, vol. 5, no. 1, Sept. 2018, pp. 1-10, doi:10.29303/spektrum.v5i1.130.