1. (a)ECHA – European Chemicals Agency (2023)Chlorosulfuric acid https://echa.europa.eu/de/brief‐profile/‐/briefprofile/100.029.304(accessed 21 July 2023).
2. (b)ECHA – European Chemicals Agency (2023)Hydrogen chloride https://echa.europa.eu/de/brief‐profile/‐/briefprofile/100.028.723(accessed 21 July 2023).
3. (c)ECHA – European Chemicals Agency (2023)Sulfur trioxide https://echa.europa.eu/de/brief‐profile/‐/briefprofile/100.028.361(accessed 21 July 2023).
4. Pyrosulfurylchlorid und Chlorsulfonsäure