Saragih, Ivany, 		Sudiana Mahendra, Made, AND 		Sudarma, I Made.
" VALUASI EKONOMI  JASA LINGKUNGAN EKOSISTEM HUTAN TAMAN EDEN 100, DESA LUMBAN JULU, PARAPAT, SUMATERA UTARA" <em>ECOTROPHIC : Jurnal Ilmu Lingkungan (Journal of Environmental Science)</em> [Online], Volume 13 Number 2 (9 January 2020)