1. H. N. Yoon, H. C. Chung, J. H. Jang, and U. Y. Kong. Use of Pyroglutamic Acid for Improving the Gastroenteric Trobles and Treatment of the Gastroenteric Disorders, and Beverages Containing the Same (Cheil Jedanang, S. Korea, 1999).
2. P. J. Rennie, S. P. King, K. A. Biedermann, and J. M. Jeffrey, PCT Int. Appl. (2001).
3. R. B. Turner, K. M. Biedermann, J. M. Morgan, B. Keswick, K. D. Keith, and M. F. Barker, Antimicrob. Chemother. 48, 2595 (2004).
4. R. F. Evans, E. F. G. Herington, and W. Kynaston, Trans. Faraday Soc. 49, 1284 (1953).
5. H. Geoffroy, Parfuemerie Kosmetik 72, 94 (1991).