@article {147403,
	title = {Studies on recent virus field variant isolates: 3. Immunogenicity of this variant strain compared with a classical strain in broiler chickens. },
	journal = {Assiut Vet. Med. J. },
	volume = {51},
	year = {2005},
	pages = { 321-335},
	author = {S.A. Nassef and Elham, A. El-Ebiary and K.M., Shaban and M.M. Amer}
}
