1. The value of a database in surveillance and vaccine selection;Macken,2001
2. Codon-substitution models for heterogeneous selection pressure at amino acid sites;Yang;Genetics,2000
3. PAML: a program package for phylogenetic analysis by maximum likelihood;Yang;CABIOS,1997
4. Felsenstein, J., 2002. PHYLIP (Phylogeny Inference Package) version 3.6a3. Distributed by the author. Department of Genome Sciences, University of Washington, Seattle. (http://evolution.gs.washington.edu/phylip.html).
5. Antigenic and genetic analyses of influenza B viruses isolated in Lusaka, Zambia in 1999;Muyanga;Archives of Virology,2001