@inproceedings{smith90graph,
  author = "A. Smith",
  title = "A problem in Graph Theory",
  booktitle = "Proceedings of International Conference on Graph Theory",
  pages = "300--311",
  address = "New York, NY",
  month = jan,
  year = 1990
};
@article{zhang91ai,
  author = "B. Zhang and H. Advisor",
  title = "First Algorithm to Solve the Problem and Its application to {AI}",
  journal = "Journal of Problems and Solutions in Artificial Intelligence",
  pages = "120--136",
  volume = "3",
  number = "9",
  month = jan,
  year = 1991
};
@mastersthesis{zhang92ai,
  author = "B. Zhang",
  title = "The Problem: algorithms and application to {AI}",
  school = "National University of USA",
  address = "Santa Claus, CA",
  year = 1992,
};
@book{kovsky92diff,
  author = "C. Kovsky and D. Chev and E. Kov",
  title = "A Slightly Different Formulation of The Problem",
  publisher = "Russian National Publisher",
  address = "Moscow, Russia",
  year = "1992",
};
@techreport{ali94diff,
  author = "M. Ali and N. Raman",
  title = "Some algorithm to solve a problem in Computer Science",
  institution   = "Institute of Study, Malaysia",
  address       = "Kuala Lumpur, Malaysia",
  number        = "ISM-TR-506",
  month         = aug,
  year          = "1994",
};