@article{RSMUP_2008__120__157_0,
     author = {Mozgawa, Witold},
     title = {Bar {Billiards} and {Poncelet's} {Porism}},
     journal = {Rendiconti del Seminario Matematico della Universit\`a di Padova},
     pages = {157--166},
     publisher = {Seminario Matematico of the University of Padua},
     volume = {120},
     year = {2008},
     mrnumber = {2492656},
     language = {en},
     url = {http://www.numdam.org/item/RSMUP_2008__120__157_0/}
}