Infrared absorption by a tunneling proton in crystalline 5-bromo-9-hydroxyphenalenoneT. Matsuo, K. Kohno, M. Ohama, T. Mochida, A. Izuoka and T. SugawaraEurophys. Lett., 47 1 (1999) 36-41DOI: https://doi.org/10.1209/epl/i1999-00347-0