body: Almost finish with writing a business book - and am going through some of the illustrations to make sure I have copyright permissions and attributions. Here's a problem I've encountered:
  
  
  There are a few photos that are from World War 2 era (battlefield photos in France, for instance), that are generally very common on the web - and I cannot find any attribution - let alone license information for these photos. Another photo or two is very specific (Cargo Cults) and the few photos available also have no source or attribution - but are used just about everywhere. 
  
  
  I'm pretty good at searching, and diving deep. I've also checked AP, Getty images, other commercial sites and also the Smithsonian archives. Nothing.
  
  
  So - what do I do? I don't want to get sued after the book is published, or charged extortion after-the-fact, or worse, have to reprint the book without the photos.
  
  
  REWORDING the main question for clarity (and so others don't think I am asking for legal advice:
  
  
  My question is not generally not "how can I search online to find the original image". 
  
  
  The question is - how can I properly use and attribute a photo inside my book - when no official attribution or copyright can be found?
  
  
  Note: 1) this is a writer's question tagged under the "copyright" tag. in all of stack exchange there is no place more appropriate than here.
  
  
  
title: Old Photo copyright