YouTube. ISO 14031, The Business Value of Environmental Performance Evaluation.
Chicago-čujuhus (17. p.)YouTube. ISO 14031, The Business Value of Environmental Performance Evaluation.
MLA-čujuhus (9. p.)YouTube. ISO 14031, The Business Value of Environmental Performance Evaluation.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.