“EXTRACTION ABSORBTIOMETRIC DETERMINATION OF AMPICYLINE BY OXASINE BASIC DYE NILE BLUE ‘B’”. Proceedings of the YSU B: Chemical and Biological Sciences, vol. 36, no. 3 (199), Sept. 2002, pp. 61-64, https://doi.org/10.46991/PYSUB.2002.36.3.061.