Stevens, Kenneth N.; Keyser, Samuel Jay (1989). "Primary Features and Their Enhancement in Consonants". Language. JSTOR. 65 (1): 81. doi:10.2307/414843. ISSN0097-8507.
Salah satu proponennya seperti pada Chomsky, 1991, Chomsky, Noam (1991). The sound pattern of English. Cambridge, Mass: MIT Press. ISBN978-0-262-03179-0. OCLC778785348.
Stevens, Kenneth N.; Keyser, Samuel Jay (1989). "Primary Features and Their Enhancement in Consonants". Language. JSTOR. 65 (1): 81. doi:10.2307/414843. ISSN0097-8507.