Detail of Portrait of a Young Man

Portrait of a Young Man, attributed to Hans Holbein the Younger. c.1520s.

I do not know where I got this image, as current searches on my computer, and on the Internet, are not giving me my exact source. I have found another copy on wikimedia commons, but not the additional detailed shots I found before. If you recognize this image and know where it originates from, please contact me as I would like to provide full credit.