Dung, N.T., Bau, L.H., Thao, L.Q. and Dat, N.D. 2017. Extractive spectrophotometric methods for determination of ciprofloxacin in pharmaceutical formulations using sulfonephthalein acid dyes. Vietnam Journal of Chemistry. 55, 6 (Dec. 2017), 767. DOI:https://doi.org/10.15625/2525-2321.2017-005341.