Elektrodynamische Maaßbestimmungen : insbesondere Zurückführung der Stromintensitäts-Messungen auf mechanisches Maass (with Wilhelm Weber) 1857. "Electrodynamic Measurements, Especially Attributing Mechanical Units to Measures of Current Intensity". German text. English translation
^Assis, Andre Koch Torres. "On the First Electromagnetic Measurement of the Velocity of Light by Wilhelm Weber and Rudolf Kohlrausch". In Bevilacqua, F; Giannetto, EA (eds.). Volta and the History of Electricity(PDF). Universita degli Studi di Pavia and Editore Ulrico Hoepli. p. 280. Retrieved 11 March 2023. Weber and Kohlrausch found √2 c = 4.39 x 10^8 m/s, such that c = 3.1 x 10^8 m/s