1. Orelup RB. inventor; Morton-Norwich Products Inc., assignee. Marker for Petroleum Fuels. United States patent US 4209302A. June 24; 1980.
2. Smith MJ, Newtown PA, Desai B, Ringwood NL. inventors; United color Manufacturing Inc., assignee. Colorless Petroleum Markers. United States patent US 6002056A, December 14; 1999.
3. Banavali RM, Stephens RW. inventors; Rohm and Haas Company, assignee. Chemical Markers. United States patent US 7858373B2; 2010 December 28.
4. Parkes J, Parkes M. inventors; Inter-Euro Technology Limited, assignee. Improved Fuel Markers. European patent EP 2738154A1; 2014 June 04.
5. Green GD, Swedo RJ, Buttrick R. inventors; Rohm and Haas Company, Dow Global Technologies LLC., assignees. Bisphenol A Compounds Useful as Markers for Liquid Hydrocarbons and Other Fuels and Oils. United States patent US 9335316B2; 2016 May 10.