Comment by progval

Why wget|dpkg and wget|sh instead of apt to download Pandoc and Calibre?

You should be able to replace all this:

    !wget https://github.com/jgm/pandoc/releases/download/2.11.3.2/pandoc-2.11.3.2-1-amd64.deb
    !sudo dpkg -i pandoc-2.11.3.2-1-amd64.deb
    !apt install libgl1-mesa-glx -y
    !wget -q -O- https://download.calibre-ebook.com/linux-installer.sh | sudo sh /dev/stdin

With simply this:

    !apt install pandoc calibre