S.- ichi Sasaki, G. Monma, D. Citterio, K. Yamada, and K. Suzuki, “Fluorescence Enhancement Detection of Underivatized Amino Acids Using a Trifluoroacetophenone-Based Tripodal Fluoroionophore”, Chimia, vol. 59, no. 5, p. 204, May 2005.