The original paper from 1973, albeit behind a paywall :-( https://doi.org/10.1029/JA078i001p00092 https://doi.org/10.1029/JA078i001p00092 Use your preferred t

The original paper from 1973, albeit behind a paywall :-( https://doi.org/10.1029/JA078i001p00092 https://doi.org/10.1029/JA078i001p00092 Use your preferred true open library to get it ;-)