This comic was available as a free insert in the following Marvel comics dated July 1999:
Spider-Girl #10 (1998 series)
Spider-Man: Chapter One #9 (1998 Series)
Mutant X #10 (1998 series)
A-Next #10 (1998 Series)
Fantastic Four #19 (1998 Series)
Generation X #53 (1994 Series)
It was inserted between pages and could be easily removed. It was not bound into the larger comic.
It was also available via mail order with the other three issues from Kidz Water.