(2015). one step ahead: Towards environmental sustainability. united nation.
Chicago-čujuhus (17. p.)One Step Ahead: Towards Environmental Sustainability. cairo: united nation, 2015.
MLA-čujuhus (9. p.)One Step Ahead: Towards Environmental Sustainability. united nation, 2015.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.