Holler, Anke. 2009. Towards an analysis of the adverbial use of German interrogative was (ˋwhat’). Proceedings of the 16th International Conference on Head-Driven Phrase Structure Grammar 131–149. (doi:10.21248/hpsg.2009.7) (https://proceedings.hpsg.xyz/article/view/717) (Accessed April 29, 2024.)