 |
| |||
| fundamental reference system of the CCITT | |||
| |||
| master telephone transmission reference systems of the CCITT | |||
The server is undergoing maintenance and the site is working in read-only mode. Please check back later.">Add | The server is undergoing maintenance and the site is working in read-only mode. Please check back later.">Report an error
| Get short URL | Language Selection Tips