Yao Xingdong, Liu Jinchun, Cheng Jieke, Zeng Yun'e . Speciation Study of Trace Elements by Reversed Phase-High Performance Liquid Chromatography (Ⅰ)——Simultaneous Determination of Cr(Ⅲ) and Cr(Ⅵ)[J]. Chemical Research in Chinese Universities, 1991, 7(1): 37-41.