1. Taccardi B. Acta Cardiologica 1958;13:173.
2. Rijlant P. Bull Acad Roy Med Bel 1959;24:718–745.
3. Gabor D, Nelson CV. J Appl Physics 1954;25:413–416.
4. Geselowitz DB. IEEE Trans Biomed Eng 1977;24:242–252.
5. Helm RA, Chou TC. In: Vectorcardiography (eds.) I Hoffman, RI Hamby, E Glassman. North-Holland, Amsterdam 1971; pp. 98–106.