SEP 1980: Charles LaFara incorporates the 99/4 Home Computer Users Group in Oklahoma City, Oklahoma. 
In its four and one-half year life the organization will move to larger headquarters in Bethany, Oklahoma, it will produce a respected newsletter, and a professional 99/4 specific magazine, it will grow to a claimed membership of over 100,000 users

99/4 Home Computer Users Group was the first magazine. It subsequently became the International 99/4 Home Computer Users Group - IUG.

IUG are issues of the International User Group newsletter.  These
apparently preceeded the Enthuisast 99 magazine.

REMV are issues of the 99/4A Program Exchange newsletter REMarks. 
The first issue I have is Volume 2 Number 4 so there are no doubt many missing.