NF X08-020-3*NF ISO 3864-3:2012 Graphical symbols - Safety colours and safety signs - Part 3 : design principles for graphical symbols for use in safety signs
2012NF X08-020-3*NF ISO 3864-3:2012 Graphical symbols - Safety colours and safety signs - Part 3 : design principles for graphical symbols for use in safety signs