1. G. P. Gross, W. F. Biller, D. F. Greene and K. K. Kearby, U. S. Patent 3,370,914
2. Selective catalytic reaction of hydrogen with nitric oxide in the presence of oxygen
3. Metal Support and Metal Additive Effects in Catalysts;Yao,1982
4. Metal-support interaction in automotive exhaust catalysts: Rh-washcoat interaction
5. H. K. Stepien, W. B. Williamson and H. S. Gandhi, SAE Paper 800843, Dearborn, MI, 1980