S. A. Siddiqui, M. Z. Ali, T. M. Mirza, and A. Z. Asghar, “A STUDY OF DOPPLER WAVEFORM PATTERN OF HEPATIC VEINS IN PATIENTS OF ACUTE VIRAL HEPATITIS IN COMPARISON WITH CONTROL POPULATION”, PAFMJ, vol. 61, no. 4, pp. 574–8, Dec. 2011.