Question: For which invention are both Christian Friedrich Schönbein, a the German-Swiss chemist and William Robert Grove, the Welsh judge and physical scientist given credit?
Sentence (from "Christian Friedrich Schönbein"): Christian Friedrich Schönbein (18 October 1799 – 29 August 1868) was a German-Swiss chemist who is best known for inventing the fuel cell (1838) at the same time as William Robert Grove, Robert Cumming and his discoveries of guncotton and ozone.
Relevant evidence: Yes