| Abstract | Description | Claims | Search report | Cited references |
| US2493038A | [0003] |
| US20050070614A | [0003] |
| WO2007136425A2 | [0003] [0010] |
| EP3071549A1 | [0003] [0010] |
| WO2018208701A1 | [0003] [0003] |
| EP19176382A | [0003] [0003] |
| The reaction of methanesulfonic acid with sulfur trioxide | [0003] |