Soumillion, J.-P., Vandereecken, P., Vanderauweraer, M., Deschryver, FC., & Schanck, A. (1989). Photophysical Analysis of Ion-pairing of Beta-naphtholate in Medium Polarity Solvents - Mixtures of Contact and Solvent-separated Ion-pairs. Journal of the American chemical society, 111(6), 2217-2225. https://doi.org/10.1021/ja00188a041 (Original work published 1989)