M. H. ruzzamanv, G. M. M. Rahman, A. S. M. Kamal, M. H. Kahil, M. A. Hossain, and A. I. Mustafa, “?SPECTROPHOTOMETRIC DETERMINATION OF PA-LLADIUM (II) WITH RUBEANIC ACID (RA) IN PRESENCE OF PYRIDINE, PIPERIDINE AND 3-PICOLINE”, Pakistan Journal of Scientific & Industrial Research, vol. 42, no. 4, pp. 173–176, Aug. 1999.