00299nam a2200109Ia 4500008004100000082001000041082000800051245010500059245000800164260000800172300000900180231017s9999    xx            000 0 und d  a624.1  bBSI 0a"Stairs, Ladders and Walkways - Part2: Code of Practice for the Design of Helical and Spiral Stairs" 0cBSI  bBSI  c30cm