1959, A. F. Trotman-Dickenson,Free Radicals: An Introduction[1], page45:
The dissociation constants forethanes in which the two halves of the molecule are different are not always close to the mean of the dissociation constants of the corresponding symmetricalethanes.
1968,Transactions of the Faraday Society, volume64,page1573:
Analysis of the ethane fraction also revealed anomalous deuteration of the ethane, theethanes C2H5D, C2H4D2 and C2H3D3 being observed as well as C2H6.Ethanes with more than three D atoms were not detected.
