GHABBOUR, E. A.; DAVIES, G.; DAGGETT, J. L.; WORGUL, C. A.; WYANT, G. A.; SAYEDBAGHERI, M.-M. Measuring the Humic Acids Content of Commercial Lignites and Agricultural Top Soils in the National Soil Project. Annals of Environmental Science, [S. l.], v. 6, 2012. Disponível em: https://openjournals.neu.edu/aes/journal/article/view/v6art1. Acesso em: 23 sep. 2023.