@unpublished{rechberger19[TUW-280503], author = {Rechberger, Helmut}, title = {{H}ow to determine the circularity of real material systems}, year = {2019}, note = {eingeladen; {V}ortrag: {I}{S}{I}{E} 2019 {C}onference, {B}eijing, {C}hina; 2019-07-07 -- 2019-07-11} }