Kolb, H.-.-A., & Bamberg, E. (1977). Influence of membrane thickness and ion concentration
on the properties of the gramicidin A channel - Autocorrelation, spectral power density, relaxation and single-channel studies. Biochimica et Biophysica Acta: BBA, 464(1), 127-141. doi:10.1016/0005-2736(77)90376-5.