Does this ProQuest "docview" URL include a DOI? I am editing someone else's thesis. The references include ProQuest citations that look like this (where # = actual digits for an account):  


  Anderson, L. (2012, Aug 17). Learning the game from the inside out. Sports Illustrated, 1. 
  Retrieved from http://search.proquest.com/docview/1040699841?accountid=#####


Is the number string that appears after .../docview/ the same as the DOI (digital object identifier) or something else?
It's not a DOI. It's probably a ProQuest-specific identifier.

First, it's not in the correct form: DOIs look like "10.1000/xyz123".

And as a rule, to check if something is a DOI, you can enter it into the resolver on http://doi.org

Here you get a "not found" error i.e. it's not a DOI: