To cite qgraph in publications use:

Epskamp S, Cramer AOJ, Waldorp LJ, Schmittmann VD, Borsboom D (2012). “qgraph: Network Visualizations of Relationships in Psychometric Data.” Journal of Statistical Software, 48(4), 1–18.

Corresponding BibTeX entry:

  @Article{,
    title = {{qgraph}: Network Visualizations of Relationships in
      Psychometric Data},
    author = {Sacha Epskamp and Ang\'elique O. J. Cramer and Lourens J.
      Waldorp and Verena D. Schmittmann and Denny Borsboom},
    journal = {Journal of Statistical Software},
    year = {2012},
    volume = {48},
    number = {4},
    pages = {1--18},
  }