@article {IOPORT.03571539,
    author       = {Chobanov, Ivan},
    title        = {Quelques remarques cin\'ematiques.},
    year         = {1976},
    journal      = {Godishnik na Sofijskiya Universitet. Fakultet po Matematika i Mekhanika},
    volume       = {67},
    issn         = {0081-1858, 0205-0811},
    pages        = {19-40},
    publisher    = {Sofijskiya Universitet ``Kliment Ochridski'', Sofija},
    identifier   = {03571539},
}