Amazon pulled the iPad from its Chinese storefront because of a lack of authorization, sources for the Wall Street Journal claim. The sources add that Apple has been working with Amazon for weeks on the matter, and that the takedown has nothing to do with Proview, the company suing Apple over use of the iPad trademark in China. Amazon.cn pulled the iPad from listings earlier this week; the Journal's report doesn't explain why another retailer, Suning, also withdrew listings.