Cryptology ePrint Archive: BibTeX Citation of Report 2009/460

@misc{cryptoeprint:2009:460,
    author = {E. Rodney Canfield and Zhicheng Gao and Catherine Greenhill and Brendan D. McKay and Robert W. Robinson},
    title = {Asymptotic enumeration of correlation-immune boolean functions},
    howpublished = {Cryptology ePrint Archive, Report 2009/460},
    year = {2009},
    note = {\url{http://eprint.iacr.org/}},
}

You will need the url.sty package (comes with most LaTeX installations) for the last line. Otherwise, remove the \url command.