5Palop R, Marsal A.Auxilialy agents with non-swelling capacity used in pickling/tanning processes.Part I [J]. Journal of the Society of Leather Technologists and Chemists, 2002, 86(4): 139-142.
6Rao J R, Kanthimathi M, Thanikaivelan P, et al.Pickle- free chrome tanning using a polymeric synthetic tanning agent for cleaner leather processing [J].Clean Technolo- gies and Environmental Policy, 2004, 6(4): 243-249.
