His most noted work was the three-volume Griechisches etymologisches Wörterbuch (Greek Etymological Dictionary) written in years 1954–1972 and published in Heidelberg.
Hans mest betydande verk Griechisches etymologisches Wörterbuch (Grekisk etymologisk ordbok) i tre band skrevs åren 1954 till 1972 och gavs ut i Heidelberg.