Lehrbuch der Phonetik (Leipzig: Teubner)
Phonetische Grundfragen (Leipzig: Teubner)
Growth and Structure of the English Language (Leipzig: Teubner)
A Modern English Grammar: I, II (Heidelberg: Winter)
Sprogets logik (Copenhagen: Gyldendal)
Nutidssprog (Copenhagen: Gyldendal)
Negation in English and Other Languages (Copenhagen: Höst)
Chapters on English (London: George Allen & Unwin)
Rasmus Rask (Copenhagen: Gyldendal)