KS B ISO 10303-21-2020 Industrial automation systems and integration-Product data representation and exchange-Part 21:Clear text encoding of the exchange structures
2020KS B ISO 10303-21-2020 Industrial automation systems and integration-Product data representation and exchange-Part 21:Clear text encoding of the exchange structures
2005KS B ISO 10303-21:2005 Industrial automation systems and integration-Product data representation and exchange-Part 21:Clear text encoding of the exchange structures