Lindquist et al, 1998

Lindquist, E. D., Hetherington, T. E., & Volman, S. F. (1998). Biomechanical and neurophysiological studies on audition in eared and earless harlequin frogs ( Atelopus ). Journal of Comparative Physiology A: Sensory, Neural, and Behavioral Physiology, 183(2), 265–271. https://doi.org/10.1007/s003590050254