When I was a kid I read all the Tom Swift, Jr. books I could get my hands on from the library. A few years ago I found several of them at book fairs/used book stores and picked up a few, such as Tom Swift and His Flying Lab "by" Victor Appleton II (a collective pseudonym). I had never read the original Tom Swift books "by" Victor Appleton (also a colective pseudonym) nor was I aware that there was a third and fourth series in later years (80s and 90s). Recently I found out that many of the first series has been put online by Project Gutenberg and are conveniently available for the Kindle directly from Amazon for free. I downloaded a bunch and have begun reading them on my daily commute.