To cite package ‘ssw’ in publications use:

  Zhao M, Lee W, Garrison EP, Marth GT (2013). “SSW library: an SIMD
  Smith-Waterman C/C++ library for use in genomic applications.” _PloS
  ONE_, *8*(12), e82138. doi:10.1371/journal.pone.0082138
  <https://doi.org/10.1371/journal.pone.0082138>.

A BibTeX entry for LaTeX users is

  @Article{zhao2013ssw,
    title = {SSW library: an {SIMD} Smith-Waterman {C/C++} library for use in genomic applications},
    author = {Mengyao Zhao and Wan-Ping Lee and Erik P Garrison and Gabor T Marth},
    journal = {{PloS ONE}},
    volume = {8},
    number = {12},
    pages = {e82138},
    year = {2013},
    doi = {10.1371/journal.pone.0082138},
  }