This is a simple bash script to select and open a book using rofi and you can also search for new books form the .find_new_book option.
Put this file in your .scripts folder and run the following command in the same Directory
$ sudo chmod +x rofibookselector.sh
Then just change the $Dir variable to your books folder.
If you wish change the $Reader to your pdf/document reader, the default is zathura
./rofibookselector.sh
- rofi
- zathura
- zathuramupdf
After running the script once there will be a file called .find_new_book in your books folder, add and delete links as you please ;)