Spectral characterization and classification of Carpentier-Edwards heart valves implanted in the aortic position. - Herkole P. Sava; Peter M. Grant; J. T. E. McDonnell (IEEE Trans. Biomed. Eng., 1996)

Time-frequency and time-scale techniques for the classification of native and bioprosthetic heart valve sounds. - P. M. Bentley; Peter M. Grant; J. T. E. McDonnell (IEEE Trans. Biomed. Eng., 1998)