Hong, Wei (1998): Request patterns in Chinese and German. A cross-cultural study. München, Newcastle. LINCOM EUROPA. ISBN: 3929075997. Band 1.
Mao, J. -j (2003): Formal Representation and Semantics of Modern Chinese Interrogative Sentences. ISBN: 0302-9743. In: Lecture notes in computer science , Nr. 2588, S. 65–74.
Shi, Dingxu (1994): The Nature of Chinese Wh-Questions. Springer. In: Natural Language & Linguistic Theory 12, Nr. 2, S. 301–333. http://www.jstor.org/stable/4047795