How to find out which sites were developed by a web studio but did not include them in the portfolio?

Question

Google

Hello, here is a web studio, let's say they are ashamed of some of the work that I want to see. Although they are ashamed or simply did not have time to throw sites into the portfolio, they prescribe a link in the footer to their site and put a logo. How to find all the sites that they developed using these links there?

Answer 1

to google:"site.com"

Answer 2

If you know what logo is being placed, then just search by image.
Yes, and the search for returns to semrash and ashrefs will give the necessary information