Maran, Timo. “John Maynard Smith’s Typology of Animal Signals: A View from Semiotics”. Sign Systems Studies 37, no. 3/4 (December 1, 2009): 477–497. Accessed March 29, 2024. https://ojs.utlib.ee/index.php/sss/article/view/SSS.2009.37.3-4.05.