R.  Vaclav, Calero-Torralbo, M. A., and Valera, F., ?Ectoparasite load is linked to ontogeny and cell-mediated immunity in an avian host system with pronounced hatching asynchrony?, Biological Journal of the Linnean Society, vol. 94, pp. 463-473, 2008.

A.  Roulin, Christe, P., Dijkstra, C., Ducrest, A. - L., and Jungi, T. W., ?Origin-related, environmental, sex, and age determinants of immunocompetence, susceptibility to ectoparasites, and disease symptoms in the barn owl?, Biological Journal of the Linnean Society, vol. 90, pp. 703-718, 2007.