Cryptology ePrint Archive: BibTeX Citation of Report 2015/569

@misc{cryptoeprint:2015:569,
    author = {Bingke Ma and Bao Li and Ronglin Hao and Xiaoqian Li},
    title = {Improved (Pseudo) Preimage Attacks on Reduced-Round GOST and Grøstl-256 and Studies on Several Truncation Patterns for AES-like Compression Functions (Full Version)},
    howpublished = {Cryptology ePrint Archive, Report 2015/569},
    year = {2015},
    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.