@article{701664,
     title = {Foreword},
     booktitle = {Proceedings of the 20th Winter School "Geometry and Physics"},
     series = {GDML\_Books},
     publisher = {Circolo Matematico di Palermo},
     address = {Palermo},
     year = {2001},
     pages = {7-7},
     url = {http://dml.mathdoc.fr/item/701664}
}

Slovák, Jan; Čadek, Martin. Foreword, dans Proceedings of the 20th Winter School "Geometry and Physics", GDML_Books,  (2001), p. 7. http://gdmltest.u-ga.fr/item/701664/