@article{li_gao_gao_wang_zhang_2015,  title={CHARACTERIZATION OF BULK SOIL HUMIN AND ITS ALKALINE-SOLUBLE AND
					ALKALINE-INSOLUBLE FRACTIONS},  volume={39},  ISSN={0100-0683},  url={https://doi.org/10.1590/01000683rbcs20150294},  DOI={10.1590/01000683rbcs20150294},  number={1},  journal={Revista Brasileira de Ciência do Solo},  publisher={Sociedade Brasileira de Ciência do Solo},  author={Li, Cuilan and Gao, Shuqing and Gao, Qiang and Wang, Lichun and Zhang, Jinjing},  year={2015},  month={Jan},  pages={120–126} }