AUTHOR=Heijungs Reinout , Allacker Karen , Benetto Enrico , Brandão Miguel , Guinée Jeroen , Schaubroeck Simon , Schaubroeck Thomas , Zamagni Alessandra TITLE=System Expansion and Substitution in LCA: A Lost Opportunity of ISO 14044 Amendment 2 JOURNAL=Frontiers in Sustainability VOLUME=2 YEAR=2021 URL=https://www.frontiersin.org/journals/sustainability/articles/10.3389/frsus.2021.692055 DOI=10.3389/frsus.2021.692055 ISSN=2673-4524