1421 : The Year China Discovered America / by Gavin Menzies ; narrated by Simon Vance
— feeling doubt 
This book sounded good. And then I started to read it. I am stopping not even 50% into it, because I have discovered myself regularly asking questions like, "How in the world does the author know that?" Or, "so, besides being a submarine commander, what else qualifies this author to make these assertions?" Or the one that really sets my alarm bells off, "Wait a minute. HE discovered this?! Is he telling me that no other scholar in the world for the last 600 years has noticed the things that he is claiming?" Um, nope. At best I am dubious about this author's scholarly authority with regard to this topic.
2