Hossain, M. “Alarming Pandrug Resistance (PDR), Extensive Drug Resistance (XDR), and Multidrug Resistance (MDR) Gram-Negative Bacilli”. Journal of Current and Advance Medical Research, vol. 2, no. 1, Mar. 2015, pp. 1-2, doi:10.3329/jcamr.v2i1.22578.