Βιβλιογραφική Τεκμηρίωση:
The Unprecedented COVID-19 Crisis. Thomas SL.J Nurse Pract. 2020 Apr;16(4):A9.
Unprecedented pandemic, unprecedented shift, and unprecedented opportunity. Yan Z.Hum Behav Emerg Technol. 2020 Apr 6:10.1002/hbe2.192.
Unprecedented Events do not Always Call for Unprecedented Actions.Shrivastava D.Sleep Vigil. 2020 May 25:1-2.