To cite ASMap in publications use:

  Julian Taylor, David Butler (2017). R Package ASMap: Efficient
  Genetic Linkage Map Construction and Diagnosis. Journal of
  Statistical Software, 79(6), 1-29. doi:10.18637/jss.v079.i06

A BibTeX entry for LaTeX users is

  @Article{,
    title = {{R} Package {ASMap}: Efficient Genetic Linkage Map Construction and Diagnosis},
    author = {Julian Taylor and David Butler},
    journal = {Journal of Statistical Software},
    year = {2017},
    volume = {79},
    number = {6},
    pages = {1--29},
    doi = {10.18637/jss.v079.i06},
  }