US office
P.O.Box 4481
Naperville, IL 60565
USA

Phone: 309-826-8662
Fax: 309-294-8811
ch@gcmag.com

China office
107 Fen Xiang, 100088 Xin Xiang
Beijing 100088, P.R. China

Phone: (86-010) 62044843
Fax: (86-010) 62366507