Physical principles of ultrasonic diagnosis / P. N. T. Wells. Wells, P. N. T. Diagnostic ultrasonic imaging. RC78.7 .U4 W45 RC78.7.U4 W45 616.075 WEP Includes bibliographical references and index. London : Academic Press, c1969. c1969. 1969 Text viii, 282 p. : eng Medical physics series ; v. 1