1855, France. Camille Durutte, Influence de l'élasticité dans les cordes vibrantes, loi remarquable découverte par M. le colonel N. Savart f
1870, Germany. Hermann von Helmholtz, Klänge der Saiten. g
1870, England. William Fishburn Donkin, Application to Metallic Wire
1877, England. John Strutt, Transverse Vibrations of Strings
1884, England. A. J. Hipkins, Observations on the Harmonics of a String struck at one-eighth of its Length