How to link to a Google Scholar entry? I have seen websites with links to specific Google Scholar entries, i.e. for this publication here. 

How can you link to a specific entry? It seems like when I click the title of a paper, it either follows the link to the publication or opens a pop-up window with more (and editable) information.
Looking at the website you cited (matt-koehler.com/vita) He is evidently just linking to the cluster page.

Here is how I was able to recreate that sort of link:

Go to your Google Scholar profile. Click on the paper you want to link. The pop-up window you mention will appear. At the bottom of the pop-up, there is a link that says "All X versions" where X is some number. That link will contain the URL you want.