@software{egon_willighagen_2015_20717, author = {Egon Willighagen and Ryan Kohl and Carl Boettiger}, title = {rrdf: Release 2.2.1}, month = jul, year = 2015, publisher = {Zenodo}, version = {rrdf\_2.1.1}, doi = {10.5281/zenodo.20717}, url = {https://doi.org/10.5281/zenodo.20717} }