“OPTIMISATION AND VALIDATION OF HPLC METHOD FOR SIMULTANEOUS QUANTIFICATION OF RIFAMPICIN, ISONIAZID, PYRAZINAMIDE, AND ETHAMBUTOL HYDROCHLORIDE IN ANTI-TUBERCULOSIS 4-FDC TABLET”. Jurnal Teknologi, vol. 77, no. 1, Oct. 2015, https://doi.org/10.11113/jt.v77.3870.