% One entry per reference. The key (smith2021) is what you pass to \cite.
@article{smith2021,
  author  = {Alice Smith and Bharat Rao},
  title   = {Two step calibration of low cost temperature sensors},
  journal = {Journal of Atmospheric Measurement},
  volume  = {14},
  number  = {3},
  pages   = {201-218},
  year    = {2021}
}

@inproceedings{lopez2019,
  author    = {Marta Lopez and Yusuf Demir},
  title     = {Joint estimation of instrument bias in dense sensor networks},
  booktitle = {Proceedings of the Conference on Environmental Sensing},
  pages     = {77-86},
  year      = {2019}
}

@article{hernandez2020,
  author  = {Paulo Hernandez},
  title   = {A public record of urban temperature at street level},
  journal = {Data in Environmental Science},
  volume  = {6},
  pages   = {45-59},
  year    = {2020}
}

@article{okafor2022,
  author  = {Ngozi Okafor and Lars Vogel},
  title   = {Long term drift in inexpensive temperature sensors},
  journal = {Sensors and Actuators},
  volume  = {338},
  pages   = {112-124},
  year    = {2022}
}