Cryptology ePrint Archive: BibTeX Citation of Report 2009/094

@misc{cryptoeprint:2009:094,
    author = {Sugata Gangopadhyay, Sumanta Sarkar, Ruchi Telang},
    title = {On the Lower Bounds of the Second Order  Nonlinearity of some Boolean Functions },
    howpublished = {Cryptology ePrint Archive, Report 2009/094},
    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.