Melo, A. A. B. de (2016) “Spatial distribution of organic carbon and humic substances in irrigated soils under different management systems in a semi-arid zone in Ceará, Brazil”, Semina: Ciências Agrárias, 37(4), pp. 1845–1856. doi: 10.5433/1679-0359.2016v37n4p1845.