Mahdalena and Hamidah (2026) “Synergistic Effect of Shrimp Shell Liquid Organic Fertilizer and Phonska NPK on the Growth of Robusta Coffee (Coffea canephora) Seedlings: Sinergi POC Kulit Udang dan NPK Phonska dalam Meningkatkan Pertumbuhan Bibit Kopi Robusta (Coffea canephora)”, Agrifarm: Jurnal Ilmu Pertanian, 15(1), pp. 105–116. doi: 10.24903/ajip.v15i1.4031.