@misc{lookslikeit,
  author={Krawetz, Neal},
  title={Looks Like It},
  url={http://www.hackerfactor.com/blog/?/archives/432-Looks-Like-It.html}
}

@article{tang2012perceptual,
  title={Perceptual hashing for color images using invariant moments},
  author={Tang, Zhenjun and Dai, Yumin and Zhang, Xianquan},
  journal={Appl. Math},
  volume={6},
  number={2S},
  pages={643S--650S},
  year={2012},
  url={http://www.phash.org/docs/pubs/thesis_zauner.pdf}
}

@article{zauner2010implementation,
  title={Implementation and benchmarking of perceptual image hash functions},
  author={Zauner, Christoph},
  year={2010},
  publisher={na}
}