One after another, continually, constantly. I have massive, sagging book cases and piles stacked everywhere--annoys the hell out of my orderly, organized INFJ, but many of the books are hers. Kindles and nooks (and the like) are for wimps and tight asses (arses). When I become demented and have to move to an assisted living facility, my kids are going to have one hell of a time with this solid mass of intellectual detritus. Serves them right for not calling me often enough.