@inproceedings{Xiao:2024ut,
  author = "Xiao, Zhiguang  and  Zhou, Zhi-Yong",
  title = "{Theoretical aspects of virtual states, bound states, and resonances in hadron physics from Friedrichs model}",
  doi = "10.22323/1.413.0004",
  booktitle = "Proceedings of The 10th International Workshop on Chiral Dynamics {\textemdash} PoS(CD2021)",
  year = 2024,
  volume = "413",
  pages = "004"
}