I first came across an article in 1981 talking about these cycles and I tried to calculate where the highs and lows would be going forward in a very amateur manner.........but coincidently Zeal about a month ago had a fairly good article explaining the 34 and 17 year cycle. I didn't keep it but I'm sure it can be found somewhere but this is an article of his from 2009. http://www.zealllc.com/2009/bearcyc.htm
After reading Cowan's pentagonal article my head is now spining...LOL