APA-ийн эшлэл(7 дахь хэвлэлт)

ebrary, Inc, Kügler, F., Féry, C., & Vijver, R. F. H. E. v. d. (2009). Variation and gradience in phonetics and phonology. Mouton de Gruyter.

Чикаго-гийн эшлэл (17 дахь хэвлэлт)

ebrary, Inc, Frank Kügler, Caroline Féry, ба Ruben Florentius Hendricus Eduardus van de Vijver. Variation and Gradience in Phonetics and Phonology. New York, NY: Mouton de Gruyter, 2009.

MLA -ийн эшлэл (9 дэх хэвлэлт)

ebrary, Inc, et al. Variation and Gradience in Phonetics and Phonology. Mouton de Gruyter, 2009.