Foot Drawing Reference

Your question is actually about two things: How to produce a footnote, and how to embed a citation to a reference (here: an URL) into such a note. Footnotes are produced with the standard LaTeX command \footnote{}. LaTeX will add a superscript number at the position in the running text where you used \footnote, and will add the same number plus at the bottom of the page ...
foot drawing reference 1

The New York Times: His Right Foot: One Tiny Drawing for Sale, Said to Be by Michelangelo

foot drawing reference 2

His Right Foot: One Tiny Drawing for Sale, Said to Be by Michelangelo

Seattle Times: His right foot: 1 tiny drawing for sale, said to be by Michelangelo

His right foot: 1 tiny drawing for sale, said to be by Michelangelo

foot drawing reference 5

I am using \columns in beamer to show two pictures. After I added \footnote{ExampleText} after captions, the ExampleTest just appear in each column. Now I want to show all of the ExampleText in the bottom of the slide instead of each column, how can I do this? MWE:

How to display the footnote in the bottom of the slide while using ...

So here an example with only one measure per head an foot: ... Now, you can remove the % before some of the options to see, how the influence the size and position of page header and page footer. For example here an example that shows the change, from the example above to an example with headheight=60pt,headinclude=true,footheight=60pt ...

You simply add the number of the footnote that you want repeated for a certain author. The number here is [2] as you have a footnotemark for the title which takes number 1. The first author and the second author share footnotemark number [2]. The second author has an additional footnotemark [3] if you want to repeat it elsewhere and so on.