To cite package 'deSolve' in publications use:

  Karline Soetaert, Thomas Petzoldt, R. Woodrow Setzer (2010). Solving
  Differential Equations in R: Package deSolve. Journal of Statistical
  Software, 33(9), 1--25. doi:10.18637/jss.v033.i09

A BibTeX entry for LaTeX users is

  @Article{,
    title = {Solving Differential Equations in {R}: Package de{S}olve},
    author = {{Karline Soetaert} and {Thomas Petzoldt} and {R. Woodrow Setzer}},
    journal = {Journal of Statistical Software},
    volume = {33},
    number = {9},
    pages = {1--25},
    year = {2010},
    doi = {10.18637/jss.v033.i09},
    keywords = {ordinary differential equations, partial differential
    equations, differential algebraic equations, initial value problems,
    R, FORTRAN, C},
  }