Archive issues of Gazette des Armes are available on-line

You may find then here:
http://fr.1001mags.com/magazine/gazette-des-armes (link)
You may read them on-line or download a *.pdf file with illustrations in high resolution only for 1 Euro per issue.

P.S. the article about espontons & hallebardes (see illustration on the left) is in Issue 204, Sept-Oct 1990 (link)