Apparently, I cannot comment on other people's posts yet. That's why I open this new question, referring to this one. I am using the code given in Fran's answer. Now, I wonder, how could I include two subtitles to the title? And then center the title in the vertical center as well as in the horizontal center of the page?
I would also like to have another figure at the upper right corner.
So, for some reason, the \raggedright command shifts the first figure to the upper left corner. I was trying \raggedleft then and included my other figure that I want in the upper right corner. I did this after I included the figure in the upper left corner. But these figures then are not on the same height.

\includegraphics{...}\hfill\includegraphics{...}to put two on the same line. – David Carlisle Nov 09 '18 at 19:23