src/HOL/Analysis/document/root.bib

output physical_stderr, e.g. for low-level debugging;

@article{dugundji,
  author	= {J. Dugundji},
  title		= {An extension of {Tietze's} theorem},
  journal	= {Pacific J. Math.},
  pages		= {353-367},
  volume  = 1,
  number  = 3,
  year    = 1951,
  url     = {https://projecteuclid.org/euclid.pjm/1103052106}}

@misc{dummy}