Manually import notes via copy notebook folder

[Spico Florin]

Hello!
  I would like to import notes into Zeppelin by manually overwriting the
notebook folder.
The files are copied in the notebook folder, but I cannot see them in the
Zeppelin UI.
Is any other place where Zeppelin is storing information about the
notebooks?
Besides the REST API,   to import the notes, is it possible to apply a
procedure like the described one?
I look forward for your solutions.
Thanks.
Best regards,
 Florin