1. a W.F. Gresham and C.E. Schweizer, U.S. Patent 2,534,018 (1950)
2. b W.F. Gresham, U.S. Patent 2,636,046
3. c W.F. Gresham, U.K. Patent 655,237 (1951).
4. R.L. Pruett and W.E. Walker (Union Carbide Corp.), U.S. Patent 3,833,634 (1974), and many subsequent patents; see ref. 3.
5. Homogeneous Catalytic Hydrogenation of Carbon Monoxide: Ethylene Glycol and Ethanol from Synthesis Gas