Quadros, B.R. de et al. 2011. Nutrients content in lettuce plants and seeds in function of organic compost levels, with and without added phosphorus to the soil. Semina: Ciências Agrárias. 32, 4Sup1 (Dec. 2011), 1725–1734. DOI:https://doi.org/10.5433/1679-0359.2011v32n4Sup1p1725.