Lorent, V., Claeys, W., Cornet, A., & Fussen, D. (1987). Coherent Excitation of 2 N = 3 Stark States in a Fast Hydrogen Beam and Their Evolution Inside a Time-dependent Electric-field. Journal of Physics B: Atomic, Molecular and Optical Physics, 20(8), 1875-1883. https://doi.org/10.1088/0022-3700/20/8/022 (Original work published 1987)