@article{sirres2017augmenting,

  title={Augmenting and structuring user queries to support efficient free-form code search},

  author={Sirres, Raphael and Bissyand{\'e}, Tegawend{\'e} F and Kim, Dongsun and Lo, David and Klein, Jacques and Kim, Kisub and Le Traon, Yves},

  journal={Empirical Software Engineering},

  pages={1--33},

  year={2017},

  publisher={Springer}

}