@article{CSIS_2008_5_2_a9,
     author = {David Pereira and Nelma Moreira},
     title = {KAT and {PHL} in {Coq}},
     journal = {Computer Science and Information Systems},
     publisher = {mathdoc},
     volume = {5},
     number = {2},
     year = {2008},
     url = {http://geodesic.mathdoc.fr/item/CSIS_2008_5_2_a9/}
}