Hirosuke Hirano, and Davin H. E. Setiamarga. “THE REPRODUCTION OF NATURAL SEA SLUDGE (HEDORO) USING PRESERVED NATURAL INORGANIC MATTERS”. GEOMATE Journal, vol. 16, no. 57, Dec. 2018, pp. 49-55, https://geomatejournal.com/geomate/article/view/2826.