@article{wachs2018a,
  title = {A modular bottom-up approach for constructing physical input–output tables (PIOTs) based on process engineering models}
  author = {Wachs, Liz; Singh, Shweta},
  journal = {Factor X: Challenges, Implementation Strategies and Examples for a Sustainable Use of Natural Resources},
  doi = {10.1186/s40008-018-0123-1},
  year = {2018}
}