@inproceedings{ijcai1989p253,
  title     = {Can Early Stage Vision Detect Topology},
  author    = {Liu, Lifu and Zhao, Nanyuan and Zhaoqi, Bian},
  booktitle = {Proceedings of the Eleventh International Joint Conference on
               Artificial Intelligence, {IJCAI-89}},
  publisher = {International Joint Conferences on Artificial Intelligence},
  editor    = {N. S. Sridharan},
  pages     = {1591--1594},
  year      = {1989},
  month     = {8},
  note      = {Vision and Robotics},
  url       = {https://ijcai.org/proceedings/1989/253},
}