After taking digital notes from (most) of the sources I will be using, I printed them and clustered them together with the idea they help support. The result? So many notes and surfaces full of notes that the product is not useful. The verdict: I'm moving to digital and using Gingko, my favorite outlining app. I'm excited about the idea, since that was my next step anyway. It was not all wasted effort, since by doing this I was able to think about the structure of the review.