@article{2021a,
  author = "N. Anerousis and P. Chemouil and A. A. Lazar and N. Mihai and S. B. Weinstein",
  title = "The Origin and Evolution of  Open Programmable Networks and SDN",
  year = 2021,
  journal = "IEEE Communications Surveys and Tutorials",
  volume = 23,
  number = 3,
  month = "Feb"
}