Paper  bibtex   

@book{kendall_vowels:_2014,
	Address = {Eugene, OR},
	Author = {Kendall, Tyler and Thomas, Eric R},
	Date = {2014},
	Date-Modified = {2016-09-23 19:24:08 +0000},
	Keywords = {acoustic phonetics, phonetics, R, segmental, statistics, tool, vowels},
	Publisher = {Language Variation and Computation Lab, Linguistics Department, University of Oregon},
	Title = {vowels: Vowel manipulation, normalization, and plotting},
	Url = {https://cran.r-project.org/web/packages/vowels/},
	Bdsk-Url-1 = {https://cran.r-project.org/web/packages/vowels/}}