Bush Clara N Phonetic variation and acoustic distinctive features a study of four general Ameruican fricatives - London Mouton and Co UK 1964 - Janua lkinguarum series practica ed by Cornelis H Van Schooneveld; 12 . Standard No.: 48,402 Source: Textual Subjects--Topical Terms: LINGUISTICS Dewey Class. No.: P:1, K41