Question: At which laboratory was Carsten Olsen employed as an assistant to the Danish chemist who introduced the concept of pH?
Sentence (from "Carsten Olsen"): Carsten Erik Olsen (March 1, 1891 – August 19, 1974) was a Danish plant ecologist and plant physiologist, who pioneered the study of plant nutrition in soils of different pH.
Relevant evidence: Yes