ABDEL-GAWAD, I. M., I. M. Moussa, K. F. Mohamed, and E. - J. Jakeen,  "A Panoramic View Of Infectious Coryza In Laying Hens With Special Reference To HG-2PCR.",  J. Egypt. Vet. Med. Assoc., vol. 64, no. 1, pp. 113?124, 2004.