Gebi Hiskia, Akhmad Sopian, and Mahdalena, “THE EFFECT OF UREA, KCl, SP-36 FERTILIZER ON PRODUCTION AT SOME AGE OF NATURAL RUBBER PLANT (Hevea brasiliensis Mull.Arg): PENGARUH PUPUK UREA,KCl,SP-36 TERHADAP PRODUKSI PADA BEBERAPA UMUR TANAMAN KARET ALAM (Hevea brasiliensis Mull.Arg) ”, agri. j. ilmu. pertan., vol. 11, no. 1, pp. 55–60, Jul. 2022.