1. Kanazawa T, Sakurai K (2001) SAE 2001-01-0660
2. Yamamoto S, Matsushita K, Etoh S, Takaya M (2000) SAE 2000-01-0892
3. Tourtellotte JE, Negra JS, Warshaw A, Villier-Fisher JF (1972) US Patent 3,699,683
4. Csicsery SM (1974) US Patent 3,831,572
5. Otto K, Montreuil CN, Todor O, McCabe RW, Gandhi HS (1991) Ind Eng Chem Res 30:2333