@misc{cryptoeprint:2010:521,
    author = {Xiutao Feng and Chunfang Zhou and Chuankun Wu},
    title = {Linear Approximations of Addition Modulo $2^n$-1},
    howpublished = {Cryptology ePrint Archive, Report 2010/521},
    year = {2010},
    url = {http://eprint.iacr.org/2010/521},
}