Wheaton, Bruce R. (1978). "Philipp Lenard and the Photoelectric Effect, 1889-1911". Historical Studies in the Physical Sciences. 9: 299–322. doi:10.2307/27757381. JSTOR27757381.
Wheaton, Bruce R. (1978). "Philipp Lenard and the Photoelectric Effect, 1889-1911". Historical Studies in the Physical Sciences. 9: 299–322. doi:10.2307/27757381. JSTOR27757381.