Souto, M. A. M., M. M. Okada, I. A. Okada, and S. Dovidauskas. “The Nitrate Determination in Water by UV Spectrophotometry: Uses and Precautions”. Instituto Adolfo Lutz Journal - RIAL, vol. 65, no. 1, Jan. 2006, pp. 66-70, doi:10.53393/rial.2006.65.32973.