S. Khakwani, S. Aslam, M. N. Shahi, T. Maqbool, A. M. Rolim Bernardino, and M. A. Khan, “Mass Spectrometry of Substituted Ethyl-4-anilinopyrazolo[3,4-b]pyridine-5-carboxylic Acids”, ajc, vol. 28, no. 6, pp. 1258–1260, Feb. 2016.