So it seems our Zenodo DOI buttons are down due to some Zenodo outage, e.g., I get code 503 from this: https://zenodo.org/badge/DOI/10.1007/s10817-020-09543-2.svg
I've noticed this several times in the past. It comes and goes.
But given that these Zenodo buttons do not provide any special features, we could easily replace them with
Last updated: Jun 03 2023 at 18:01 UTC