1. Air, G. M. 1981. Sequence relationships among the haemagglutinin genes of 12 subtypes of influenza A virus. Proc. Natl. Acad. Sci. USA 78: 7639–7643.
2. Apostolov, K., T. H. Flewett, and A. P. Kendal. 1970. Morphology of influenza A, B, C and infectious bronchitis virus (IBV) virions and their replication, p. 3–26. InR. D. Barry and B. W. J. Mahy (eds.), The biology of large RNA viruses, Academic Press Inc., New York.
3. Arden, N. H., P. A. Patriarca, and A. P. Kendal. 1986. Experiences in the use and efficacy of inactivated influenza vaccine in nursing homes, p. 155–168. InA. P. Kendal, P. A. Patriarca (eds.), Options for the control of influenza, Alan R. Liss, New York.
4. Aymard-Henry, M., M. T. Coleman, W. R. Dowdle, W. G. Laver, G. C. Schild, and R. G. Webster. 1973. Influenza-virus neuraminidase and neuraminidase-inhibition test procedures. Bull. W.H.O. 48: 199–202.
5. Barker, W. H. 1986. Excess pneumonia and influenza associated hospitalization during influenza A epidemics in the US, 1970–1978, p. 75–87. InA. P. Kendal, P. A. Patriarca (eds.), Options for the control of influenza, Alan R. Liss, New York.