B. R. de Quadros, F. O. Magro, C. V. Corrêa, and A. I. I. Cardoso, “Nutrients content in lettuce plants and seeds in function of organic compost levels, with and without added phosphorus to the soil”, Semina: Ciênc. Agrár., vol. 32, no. 4Sup1, pp. 1725–1734, Dec. 2011.