Paul Wight, Thomas Paul, Sarfraz Hussein, "Progress in Permanence: Improved Dyes for “Gas Fading”" in Proc. IS&T Int'l Conf. on Digital Printing Technologies (NIP19), 2003, pp 431 - 433, https://doi.org/10.2352/ISSN.2169-4451.2003.19.1.art00103_1