@incollection{sanchez2018review,
  title = {Review of the Main Security Threats and Challenges in Free-Access Public Cloud Storage Servers},
  author = {Sanchez-Gomez, Alejandro and Diaz, Jesus and Hernandez-Encinas, Luis and Arroyo, David},
  booktitle = {Computer and Network Security Essentials},
  pages = {263--281},
  year = {2018},
  publisher = {Springer, Cham}
}