Y. Zhang Iono-covalent theory applications (24)
American Huilin Institute http://www.amhuilin.com/
Dinger and Henderson proposed : “The average carbon NMR Au-CH chemical shift of 62.1 ppm for aurathietane-3,3-dioxide (6) is significantly higher than that reported for Pt- and Pd- amalogous complexes (2a) and (8),with shifts of 54.6 ppm and 52.5 ppm respectively. This is not unexpected with a more electron-deficient , central metal atom (Zhang electronegativity values for platinum(II) and gold(III) are 1.5 and 1.7) .”
 M. B. Dinger, W. Henderson Journal of Organometallic Chemistry, 1977, 547, 243-252.
 K. M. Mackay, R. A. Mackay, W.Henderson "Introduction to Modern Inorganic Chemistry", 6th ed., Nelson Thornes, United Kingdom,2002, pp 53-54).