“Third-Order Optical Nonlinearity in Guinness Stout,” F.Z. Henari and W. Blau, Photonic Science News, vol. 3, 1998, pp. 10?3.
(Thanks to Mauricio Alvarez-Manilla for bringing this to our attention.)
(That?s an excerpt from the article “May We Recommend ? Items that merit a trip to the library,” published in AIR 14:1.)