Your friend saw this resource on bethinking.org and thought you should see it:
No Lost Books of the Bible
Some people claim there are 'lost books' that should have been included in the Bible. Greg Koukl says this view doesn't make sense, whether or not you think the Bible has supernatural origins.
See the full resource online by visiting bethinking.org:
is a collection of resources which aims to make sense of the big questions of life about God, Jesus and Christianity.