ebrary, Inc, Thewissen, J. G. M., & Nummela, S. (2008). Sensory evolution on the threshold: Adaptations in secondarily aquatic vertebrates. University of California Press.

ebrary, Inc, J. G. M. Thewissen, and Sirpa Nummela. Sensory Evolution on the Threshold: Adaptations in Secondarily Aquatic Vertebrates. Berkeley: University of California Press, 2008.

ebrary, Inc, et al. Sensory Evolution on the Threshold: Adaptations in Secondarily Aquatic Vertebrates. University of California Press, 2008.