@article{hartmanis:1965,
  title={On the computational complexity of algorithms},
  author={Hartmanis, Juris and Stearns, Richard E},
  journal={Transactions of the American Mathematical Society},
  volume={117},
  pages={285--306},
  year={1965},
  publisher={JSTOR},
  doi={10.2307/1994208}
}


@book{hopcroft:2014,
year = {2014},
title = {Introduction to automata theory, languages, and computation},
edition = {3.},
language = {eng},
author = {Hopcroft, John E},
isbn = {9781292039053},
}

@book{sipser:2006,
year = {2006},
title = {Introduction to the theory of computation},
edition = {2.},
language = {eng},
author = {Sipser, Michael},
isbn = {9780619217648},
}
