9Meads R E, Malden P J. Electron spin resonance in natural kaolinites containing Fe( Ⅱ )and other transition metal ions [J ]. Clay Minerals, 1975 (10) : 313 - 345.
10Angel B R, Vieent W E J. Electron spin resonance studies of iron oxides associated with the surface of kaolins[J]. Clays and Clay Minerals, 1978 (26) : 263 - 272.
