Lit review tasks

[jvcasillas]

• [x] add bib file to repo (./docs/bib/pd_lit.bib)
• [ ] review articles in bib file, write 1 paragraph summaries
  • [ ] author (2019)
  • [ ] author ()

[jvcasillas]

To add: Leeuw & Celata, 2019 https://doi.org/10.1016/j.wocn.2019.05.003