1 Weather in Space?
Garry Toth, Author ATA Guide to Space Philately
http://americantopicalassn.org/studyunits.shtml
2 How Does Space Weather Affect Us?
GarryToth, Author ATA Guide to Space Philately
http://americantopicalassn.org/studyunits.shtml
3 A New Way to Judge Literature
John Hotchner, Co-Author of APS Literature Judging Manual
http://stamps.org/Home
4 The Process of Change
John Hotchner, Co-Author of APS Literature Judging Manual
http://stamps.org/Home