Sreekumar, R., & Jacob Philip. (1993). Investigation of phase transitions in selected high Tc superconductors and ferroelectrics using ultrasonic technique. Cochin University of Science and Technology.

Sreekumar, R., and Jacob Philip. Investigation of Phase Transitions in Selected High Tc Superconductors and Ferroelectrics Using Ultrasonic Technique. Cochin: Cochin University of Science and Technology, 1993.

Sreekumar, R., and Jacob Philip. Investigation of Phase Transitions in Selected High Tc Superconductors and Ferroelectrics Using Ultrasonic Technique. Cochin University of Science and Technology, 1993.