Effect of Silica Fillers on Characterization of Cellulose-Acrylamide Hydrogels Matrices as Controlled Release Agents for Urea Fertilizers - Swantomo, Deni; Polytechnic Institute of Nuclear Technology, National Nuclear Energy Agency, Jl. Babarsari Kotak Pos 6101 YKBB Yogyakarta 55281 (Universitas Gadjah Mada, 2014)