1. US 9. 302.971 (2016 ExxonMobil); US 9.266.809 (2016 UOP); US 9.212.121 (2015 Eastman); US 5.693.856 (1997 BOC); EP 0.858.990 (1998 Mitsui); US 5.929.274 and 6.113.866 (1999/2000 HFM); van Leeuwen‐2 p.327;
2. Kirk/Othmer‐1 Vol. 18 p.1007;
3. Ullmann Vol. 26 p.193;
4. Ullmann‐2;