Devleeschouwer, M., Lambeau, C., Vanlerberghe, D., Janssens, E., & Fayt, A. (1981). Absorption-spectroscopy of Ethylene (h212c13ch2)-c-12-c13 in the 4500-cm-1 Region. Journal of Molecular Spectroscopy, 90(1), 273-286. https://doi.org/10.1016/0022-2852(81)90345-3 (Original work published 1981)