How to cite 4ti2
4ti2 team. 4ti2 -- A software package for algebraic, geometric and combinatorial problems on linear spaces. Available at www.4ti2.de.

@Misc{4ti2,
  author =   {4ti2 team},
  title =    {4ti2---A software package for algebraic, geometric and 
              combinatorial problems on linear spaces},
  howpublished = {{A}vailable at www.4ti2.de}
}