Hi Piet,
it seems that after restoring the iPad, iTunes may not immediately install all apps, although it restores their data. So my first suggestion would that you do a "restore from backup" and select the latest backup you made before resetting the iPad.
If that does not bring back the documents you have (at least) two options:
1. in iTunes' File Sharing pane, select Notebooks and drag&drop the folders that you have previously saved to your MacBook into the fils sharing pane. This import them into Notebooks
2. With iPad and your MacBOok connected to the same wifi network, enable WifI Sharing in Notebooks and select "Share this book" from the top level book. Then, connect to Notebooks from your Mac and drag&drop your documents directly into Notebooks. - You find more about this topic in our handbook, available from http://www.notebooksapp.com/Download.html
I hope that helps.
Best,
Alfons