Postal services [documento electrónico] : quality of service: measurement of the transit time of end-to-end services for single piece priority mail and first class mail: EN 13850: Mai 2002 / European Committee for Standardization
Postal services [documento electrónico] : quality of service: measurement of loss of registered mail and other types of postal service using a track and trace system: EN 14137: September 2003 / European Committee for Standardization
EN 14534 [documento electrónico] : postal services: quality of service: measurement of the transit time of end-to-end services for bulk mail / European Committee for Standardization
CEN/TS 14773 [documento electrónico] : postal services: quality of service: measurement of loss and substantial delay in priority and first class single piece mail using a survey of test letters / European Committee for Standardization