@article{yang2021where, 

  title={Where Were the Repair Ingredients for Defects4J Bugs? Exploring the Impact of Repair Ingredient Retrieval on the Performance of 24 Program Repair Systems}, 

  author={Yang, Deheng and Liu, Kui and Kim, Dongsun and Koyuncu, Anil and Kim, Kisub and Tian, Haoye and Lei, Yan and Mao, Xiaoguang and Klein, Jacques and Bissyand{\'e}, Tegawend{\'e} F.}, 

  journal={Empirical Software Engineering}, 

  volume= {},

  number= ,

  pages= {},

  year= {2021},

  url= {},

  doi={},

  publisher={Springer}

}