BibTeX:
@inproceedings{EssmannNR-IJCAR20, author={Robin E{\ss}mann and Tobias Nipkow and Simon Robillard}, title={Verified Approximation Algorithms}, booktitle={Automated Reasoning (IJCAR 2020)}, editor={N. Peltier and V. Sofronie-Stokkermans},publisher={Springer}, series={LNCS},volume={12167},pages={12167},year=2020}Isabelle theories in the Archive of Formal Proofs