@article {Ryan1991Evolution,
	title = {Evolution of intraspecific variation in the advertisement call of a cricket frog (Acris crepitans, Hylidae)},
	journal = {Biological Journal of the Linnean Society},
	volume = {44},
	number = {3},
	year = {1991},
	month = {November},
	pages = {249{\textendash}271},
	keywords = {amphibia, bioacoustics, ecology, frogs, herps, sound},
	issn = {0024-4066},
	doi = {10.1111/j.1095-8312.1991.tb00619.x},
	url = {http://dx.doi.org/10.1111/j.1095-8312.1991.tb00619.x},
	author = {Ryan, Michael J. and Wilczynski, Walter}
}
