@article{Kiefer2011,
author = {Kiefer, Sarah and Scharff, Constance and Kipper, Silke},
year = {2011},
language = {eng},
copyright = {http://creativecommons.org/licenses/by/2.0/},
title = {Does age matter in song bird vocal interactions? Results from interactive
playback experiments},
issn = {1742-9994},
url = "http://dx.doi.org/10.17169/refubium-21465",
}