Öko-Institute. V. (2011). http://issuu.com/thema1/docs/greenevents_2011_bleher_reusablecups/16?e=0
Sustainable Event Management
A Practical Guide
A Practical Guide
Öko-Institute. V. (2011). http://issuu.com/thema1/docs/greenevents_2011_bleher_reusablecups/16?e=0