Ramezani, Z., et al. “Simultaneous Extraction and Determination of 5-Hydroxy Tryptophol and 5-Hydroxyindol-3-Acetic Acid in Urine of Alcoholism by HPLC With Fluorescence Detection”. Asian Journal of Chemistry, vol. 22, no. 9, July 2010, pp. 7013-20, https://asianpubs.org/index.php/ajchem/article/view/11942.