@article{polit1989,
  title={Essentials of nursing research: Methods, appraisal, and utilization},
  author={Denise F. Polit and Bernadette P. Hungler},
  year={1989},
  journal={Medical Entomology and Zoology},
  url={https://knowledgetrend.com/paper/essentials-of-nursing-research-methods-appraisal-and-utilization}
}