Panjwani, Indra, et al. “Determination of Dopamine, Glycine, Tryptohan, Valine, Leucine and Isoleucine Using 4-Dimethylaminobenzaldehyde by HPLC in Pharmaceutical Samples”. Asian Journal of Chemistry, vol. 26, no. 22, Nov. 2014, pp. 7494-8, doi:10.14233/ajchem.2014.16631.