Vigier, F. M. ; Shimon, D. ; Mugnaini, V. ; Veciana, J. ; Feintuch, A. ; Pons, M. ; Vega, S. ; Goldfarb, D. . The 13C Solid Dnp Mechanisms With Perchlorotriphenylmethyl Radicals - The Role Of 35,37Cl. Physical Chemistry Chemical Physics 2014, 16, 19218–19228.