TO cite CHRONOS software package please cite the following paper:

  Vrahatis, A. G., Dimitrakopoulou, K., Balomenos, P., Tsakalidis, A.
  K., & Bezerianos, A. (2015). CHRONOS: A time-varying method for
  microRNA-mediated sub-pathway enrichment analysis. Bioinformatics
  (2016) 32 (6) : 884-892

A BibTeX entry for LaTeX users is

  @Article{,
    author = {Aristidis G Vrahatis and Konstantina Dimitrakopoulou and Panos Balomenos and Athanasios Tsakalidis and Anastasios Bezerianos},
    title = {{CHRONOS}: A time-varying method for microRNA-mediated sub-pathway enrichment analysis},
    journal = {Bioinformatics},
    year = {2016},
    volume = {32},
    number = {6},
    pages = {884-892},
  }