My dad used to subscibe to this.  When he passed away, I took all of them.  I probably have almost every issue from the late 60s to early 90s.  Just reading through them is really cool. So many things are still relevant 40 years later and things that were unknown then are still unknown now.Even though they are old magazines, they are still valuable resources for writing serious research papers on various topics from history to culture to science.Very glad I saved them.