Recommendation X.25 (10/1984): Interface between data terminal equipment (DTE) and data circuit-terminating equipment (DCE) for terminals operating in the packet mode and connected to public data networks by dedicated circuit
['Recommendation T.90', 'Recommendation X.25 (10/1984): Interface between data terminal equipment (DTE) and data circuit-terminating equipment (DCE) for terminals operating in the packet mode and connected to public data networks by dedicated circuit', '1988-11-25', 'ITU Telecommunication Standardization Sector']