Here's some screenshots of articles and other media prints about the Pokemon Center. Credited best to my ability.
November to Remember First Anniversary Celebration; 2002. Pokemon.com
Via Electric Gaming Monthly; 2002
Via Nintendo Power Magazine; 2001
Via colorkinetics.com; 2006 (Wayback Machine)
Via License!; 2002
Pokemon Center Brochure; 2002; Donated by PikaBellchu
Via Lighting and Design + Application; January 2003. View Full Article Here.
Small advert from a Leaf Green and Fire Red Magazine insert; 2004; Donated by @tolovelfromvine
Via Pokemon Beckett Magazine Volume 4 Number 2; 2001. Article donated by Twitter user @MidniteW
Brochure Given Out by Pokemon Center; 2003ish; Donated by Twitter user @MidniteW
Via Pokemon Revista; 2001 (?)
Via Pokemon Revista; Number 22; 2001-2002(?)
Halloween Bash invitation; 2003