Vikings in America" by Graeme Davis
http://www.goodreads.com/book/show/7125270-vikings-in-america
He talks about many points in the book, some he agrees with and some he does not. What he does do is examine them and does provide references to said points. I had the same apprehension when first buying the book at a garage sale, but it was well worth the read imho. One thing I did really like about the book is that he suggests future avenues of research, etc, that have not currently been explored (usually based on acrch. evidence, or clues from the sagas, etc)
Edit: don't worry, this isnt a conspiracy-like book on how there were giant, massive settlements down the coast, etc... but it does talk about the link between greenland and the vatican, which there was, albeit a weak one... (if you start researching into the subject, etc). Anyways, cheers.
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