Short answer, you can't see them in the reader pane.
You'll find the annotations at:
Edit Metadata > Custom medata tab > Annotations
(Presuming you created a custom column called 'Annotations', which is the default name suggested by the plugin.)
tags:"=Classics.English" or tags:"=Classics.Russian" or tags:"=Classics"
can be reduced to
It will show all the files whose tags start with "Classics"
Another variation is
If you omit the ^, then it will show those files too whose tags have "Classics" in them, but not necessarily in the beginning. For ...
I used "wondershare PDF converter" to convert my pdf to epub, then I opened the epub with Calibre and removed the line breaks with these regex :
One of the reasons this can happen is if the Calibre "convert to MOBI" preferences form has the Personal Dog tag set to [PDOC]. Then it will not show up in some versions of Kindle in the list of "Books", but it will still appear under "Documents".
Is not possible to change this tag using Calibre. A workaround is to convert it back to EPUB and then again to ...
Here is a Python script I use to automate reducing the size of epub books:
$ python epub-shrink/app.py input_file.epub output_file.epub --jpeg-quality=25