Stertz, S. C. ., P. T. P. S. . Penteado, and R. J. S. de . Freitas. “Nitrites and Nitrates in Horticultures Produced by the Conventional, Organic and Hydroponic Cultivation Systems in the Metropolitan Region of Curitiba”. Instituto Adolfo Lutz Journal - RIAL, vol. 63, no. 2, Dec. 2004, pp. 200-7, doi:10.53393/rial.2004.63.34851.