• BS 6375-2-1987 Performance of windows - Specification for operation and strength characteristics.pdf
• BS 6375-1-2004 Performance of windows and doors - Classification for weathertightness and guidance on selection and specification.pdf
• BS EN 12056-1:2000 Gravity drainage systems inside buildings - General and performance requirements.pdf
• EN 14141-2004 Valves for natural gas transportation in pipelines - Performance requirements and tests .pdf