1. Fung D.T., Laberge J.G.J., Przystal F.S. (1978) Process for the reclamation of waste hydrocarbon oils,US Patent4,124,492.
2. Wolk R.H. (1976) Refining of waste lube oil to prepare usable lubestock,US Patent3,980,551.
3. Ciora J.R.J., Liu P.K.T. (2000) Refining of used oils using membrane-and adsorption-based processes,US Patent6,024,880.
4. Zykina R.F., Zaykin Y.A. (2002) Radiation technologies for production and regeneration of motor fuel and lubricants,Radiat. Phys. Chem.65, 169-172.
5. Williams M.R., Krzykawski J. (2001) Method for obtaining base oil and removing impurities and additives from used oil products,US Patent6,174,431.