MAULIDIYAH, MAULIDIYAH, AZIS, THAMRIN, SABARWATI, SITTI, AND NURDIN, MUHAMMAD. " Isolation and Identification of (-)-Usnic Acid Compound from Lichen Usnea sp. and Its Cytotoxic Activity on Murine Leukemia P388 Cell" JURNAL ILMU KEFARMASIAN INDONESIA [Online], Volume 13 Number 1 (30 April 2015)