1. Amin, O.M., 1969. Growth of the Dog TickDermacentor variabilis Say (Acarina: Ixodidae). I. Growth patterns. J. Med. Entomol., 6: 305?316.
2. Arthur, D.R., 1960. Ticks. A Monograph of the Ixodoidea. Part V. On the GeneraDermacentor, Anocentor, Cosmiomma, Boophilus & Margaropus. Cambridge University Press, Cambridge.
3. Bishopp, F.C. and Trembley, H.L., 1945. Distribution and hosts of certain North American ticks. J. Parasitol., 31: 1?54.
4. Cooley, R.A., 1938. The GeneraDermacentor andOtocentor (Ixodidae) in the United States, with Studies in Variation. National Institute of Health, Washington, DC, Bull. No. 71.
5. Laird, M. (Editor), 1984. Commerce and the Spread of Pests and Disease Vectors. Praeger, New York, 354 pp.