@misc{zimmermann2000loops,
  title={Loops and Knots as Topoi of Substance. Spinoza Revisited},
  author={Rainer E. Zimmermann},
  year={2000},
  eprint={gr-qc/0004077},
  archivePrefix={arXiv},
  primaryClass={gr-qc},
  url={https://arxiv.org/abs/gr-qc/0004077}
}