GB/T 31308.4-2023 Chinese PDF (GB/T31308.4-2023) GB/T 29077-2024 applications and materials (Chinese: 石油天然气工业

applications and materials (Chinese: 石油天然气工业 玻璃纤维增强塑料管 第1部分：词汇、符号、应用及材料)

English versions: GB/T 29479

GB/T 45305

GB/T 45227-2025_Chinese: Technical requirements for closed-off management system of chemical industry park (Chinese: 化工园区封闭管理系统技术要求)

English versions: GB/T 45495-2025

GB/T 31308.4-2023 Chinese PDF (GB/T31308.4-2023) GB/T 29077-2024 applications and materials (Chinese: 石油天然气工业GB T 31308. 4 2023_Chinese: Processes, data elements and documents in commerce, industry and administration Long term signature Part 4: Attributes pointing to proof of existence objects used in long term signature formats (Chinese: 4) Note Careful: Text of PDF is in Chinese (not English). Delivery (PDF in Chinese): 2 working hours typically, ASAP English versions: GB T 31308. 4 2023