Guoyiivan
Since your profile does not list your country I cannot give you specific information on where to obtain these two documents.
GGG-G-15 Gage Blocks and Accessories (Inch and Metric), canceled without replacement by U.S. Government.
GGG-G-17 Gage, General Purpose, canceled without replacement by U.S. Government.
Here in the United States I have used the following organization, which also has international offices:
IHS
15 Inverness Way East
Englewood CO 80112
United States
Phone: 303-397-7956 or 800-854-7179
Fax: 303-397-2740
Web:
http://global.ihs.com
Both of these documents are still available from IHS but are now superseded by ASME or ISO Standards. Perform a specific title search to find a national or international standard you are looking for.
Good Luck
Jeff Frost