1. Opre JE (2001) Environmentally friendly ink cleaning solvent. US Patent 6 284720 B1, 2001
2. Opre JE, Bergemann EP, Henneberry M (2001) Environmentally friendly solvents. US Patent 6,191,087 B1, 2001
3. Datta R, Henry H (2006) J Chem Technol Biotechnol 81:1119
4. Chambon F, Essayem N, Rataboul F, Pinel C, Cabiac A, Guillon E (2011) Process for conversion of lignocellulosic biomass or cellulose by using supported tungsten based solid Lewis acids as catalysts. WO Patent 107 712, 2011
5. Martino-Gauchi G, Teissier R (2007) Continuous method for preparing ethyl lactate. US Patent 7297809 B2, 2007