"Insect Cold Hardiness" in S. R. Leather, K. F. A. Walters, and J. S. Bale, The Ecology of Insect Overwintering (Cambridge University Press 1995): 120. ISBN9780521556705
Insects at low temperature. Lee, Richard E., Denlinger, David L. New York: Chapman and Hall. 1991. ISBN0412028018. OCLC21373194.{{cite book}}: CS1 maint: others (link)