I've been collecting magazines which contain articles dealing with Gamma World 1st edition lately, and have compiled what I believe to be a more or less exhaustive list of the professional magazines from '78 - '82 with significant GW 1e content (i.e., excluding those just with ads, reviews, or brief mentions). There may very well be fanzines or lesser-known magazines that carried GW articles during that time period, though, so I thought I'd ask you guys.. Anything missing from the list below? TIA.

The/Dragon: #8, #18, #19, #25, #52
Different Worlds: #5
White Dwarf: #16
Polyhedron: #1, #2, #3, #6 (#4 might count, has an interview with G. Jacquet in which he discusses GW extensively)

EDIT: Evidently Campaign Magazine #91 has a comparison of Metamorphosis Alpha and GW. Polyhedron 9 and 10 have "Sage Advice" for GW.