Synthesis and characterization of chitosan-modified membrane for urea slow-release fertilizers oleh Sari Edi Cahyaningrum, Retno Ariadi Lusiana, Taufik Abdillah Natsir, Fitriari Izzatunnisa Muhaimin, Andika Pramudya Wardana, Amalia Putri Purnamasari, Misni Bin Misran