The Neuraminidase Inhibitor Susceptibility Network has published a number of scientific papers on the detection and surveillance of neuraminidase inhibitor resistance.
Links are provided to the online publications, where available (please note that a subscription may be required to obtain the full text of some articles):
Monto AS, McKimm-Breschkin JL, Macken C, Hampson AW, Hay A, Klimov A, Tashiro M, Webster RG, Aymard M, Hayden FG, Zambon M (2006). Detection of influenza viruses resistant to neuraminidase inhibitors in global surveillance during the first 3 years of their use. Antimicrob Agents Chemother. Jul;50(7):2395-402.
Hayden F, Klimov A, Tashiro M, Hay A, Monto A, McKimm-Breschkin J, Macken C, Hampson A, Webster RG, Amyard M, Zambon M (2005). Neuraminidase inhibitor susceptibility network position statement: antiviral resistance in influenza A/H5N1 viruses. Antivir Ther.;10(8):873-7. Review. Erratum in: Antivir Ther. 2006;11(1):130.