@misc{indiciaecaf856519651,
  title = {A formal theory of cubical complexes Final report},
  author = {Levy, L. S. and Perlman, M. and Roth, J. P. and Wagner, E. G.},
  year = {1968},
  url = {https://ntrs.nasa.gov/citations/19690027157},
  note = {Source identifier: 19690027157}
}