@article{hsieh2005,
  title={Three Approaches to Qualitative Content Analysis},
  author={Hsiu-Fang Hsieh and Sarah E. Shannon},
  year={2005},
  journal={Qualitative Health Research},
  doi={10.1177/1049732305276687},
  url={https://doi.org/10.1177/1049732305276687}
}