The reference for the Picornaviridae section in the 9^th ICTV Report is as follows:

Knowles, N.J., Hovi, T, Hyypiä, T., King, A.M.Q., Lindberg, M., Pallansch, M.A.,  Palmenberg, A.C., Simmonds, P., Skern, T., Stanway, G., Yamashita, T. and Zell, R. (2011). Picornaviridae. In: Virus taxonomy: classification and nomenclature of viruses: Ninth Report of the International Committee on Taxonomy of Viruses. Ed: King, A.M.Q., Adams, M.J., Carstens, E.B. and Lefkowitz, E.J. San Diego: Elsevier, pp 855-880.