There are several PDF apps which could read books in PDF form, also Nokia Reading in the store along with the Kindle app all in the Microsoft store. You could also read things via the browser or save books to your skydrive account and access them on your Lumia.
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you can also help others by marking 'accept as solution'
Click on the blue Star Icon below if my advice has helped you or press the 'Accept As Solution' link if I solved your problem..