Bill Clinton Visits His 'Great Friend' George H.W. Bush

Former President George H. W. Bush tweeted a photo Monday of his visit with former President Bill Clinton, and called him "a great friend" and "best-selling author."

Clinton is on a book tour to promote "The President Is Missing," which he co-wrote with best-selling author James Patterson. The book has sold more copies in its first week than any other former fiction book in two years.

Bush, the 41st president, has dealt with health issues for the last year, and wife Barbara Bush passed away in April at the age of 92.

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