1. The common origin of precordial vibrations;Agress;Amer. J. Cardiol.,1964
2. Mechanical aspects of the heart sound emission;Cassof;Med. Progr. Technol.,1975
3. Afwijkingen in de harttonen van de ongeborenen;Eskes;Ned. T. Geneesk.,1961
4. The fetal heart, comparison of its electrical and mechanical events;Kelly;Amer. J. Obstet. Gynec.,1965
5. Cardiovascular vibratory phenomena;Kingsley,1974