To cite package 'utility' in publications use:

Reichert P, Schuwirth N, Langhans S (2013). “Constructing, Evaluating and Visualizing Value and Utility Functions for Decision Support.” Environmental Modelling and Software, 46, 283–291. doi:10.1016/j.envsoft.2013.01.017.

Corresponding BibTeX entry:

  @Article{,
    title = {Constructing, Evaluating and Visualizing Value and Utility
      Functions for Decision Support},
    author = {Peter Reichert and Nele Schuwirth and Simone Langhans},
    journal = {Environmental Modelling and Software},
    volume = {46},
    pages = {283--291},
    year = {2013},
    doi = {10.1016/j.envsoft.2013.01.017},
    keywords = {Decision support, Multi-criteria decision analysis,
      Value functions, Utility functions, Uncertainty, Environmental
      management, Ecological river assessment, River management},
  }