M. G. Sommers, J. van Egmond, J. G. Veening, K. C. Vissers, and M. Ritskes-Hoitinga, “Alternatives for Analgesiometric Tests in Animals: The Feasibility to Reduce Discomfort by Anaesthesia”, Scand J Lab Anim Sci, vol. 36, no. 3, pp. 271–281, Dec. 2009.