@article{floyd,
 author = {Floyd, Robert W.},
 title = {Algorithm 97: Shortest Path},
 journal = {Commun. ACM},
 issue_date = {June 1962},
 volume = {5},
 number = {6},
 month = jun,
 year = {1962},
 issn = {0001-0782},
 pages = {345--},
 url = {http://doi.acm.org/10.1145/367766.368168},
 doi = {10.1145/367766.368168},
 acmid = {368168},
 publisher = {ACM},
 address = {New York, NY, USA},
}

@InCollection{roy,
  author =       {Bernard Roy},
  title =        {Transitivité et connexité},
  booktitle =    {Extrait des comptes rendus des séances de l’Académie des Sciences},
  publisher = {Gauthier-Villars},
  year =      1959,
  pages =     {216-218},
  month =     {July},
  note =      {\url{http://gallica.bnf.fr/ark:/12148/bpt6k3201c/f222.image.langFR}}
}

@article{warshall,
 author = {Warshall, Stephen},
 title = {A Theorem on Boolean Matrices},
 journal = {J. ACM},
 issue_date = {Jan. 1962},
 volume = {9},
 number = {1},
 month = jan,
 year = {1962},
 issn = {0004-5411},
 pages = {11--12},
 numpages = {2},
 url = {http://doi.acm.org/10.1145/321105.321107},
 doi = {10.1145/321105.321107},
 acmid = {321107},
 publisher = {ACM},
 address = {New York, NY, USA},
}