1. Alipour, F., & Jaiswal, S. (2009). Glottal airflow resistance in excised pig, sheep, and cow larynges. Journal of Voice, 23(1), 40–50.
2. Amundin, M. (1991). Helium effects on the click frequency spectrum of the harbor porpoise, Phocoena phocoena. Journal of the Acoustical Society of America, 90, 53–59.
3. Andrew, R. J. (1976). Use of formants in the grunts of baboons and other nonhuman primates. Annals of the New York Academy of Sciences, 280, 673–693.
4. Au, W. W. L., & Suthers, R. A. (2014). Production of biosonar signals: Structure and form. In A. Surlykke, P. E. Nachtigall, R. R. Fay, & A. N. Popper (Eds.), Biosonar (pp. 61–105). New York: Springer.
5. Ballintijn, M., & ten Cate, C. (1998). Sound production in collared doves: A test of the “whistle” hypothesis. Journal of Experimental Biology, 201, 1637–1649.