Tahir, T. F., A. F. Qader, M. I. Salih, and E. Q. Rashid. “L-Tryptophan As Fluorescent Probe for Determination of Folic Acid in Some Pharmaceutical Products”. ARO-THE SCIENTIFIC JOURNAL OF KOYA UNIVERSITY, Vol. 7, no. 2, Dec. 2019, pp. 19-26, doi:10.14500/aro.10557.