@inproceedings{
    prze:05c,
    author = "Przepiórkowski, Adam",
    url = "http://nlp.ipipan.waw.pl/~adamp/Papers/2005-ltc-numbers/",
    title = "The {IPI PAN} {C}orpus in Numbers",
    pages = "27--31",
    crossref = "vetu:05:ed"
}
@proceedings{
    vetu:05:ed,
    editor = "Vetulani, Zygmunt",
    title = "Proceedings of the 2nd Language \& Technology Conference",
    booktitle = "Proceedings of the 2nd Language \& Technology Conference",
    address = "Poznań, Poland",
    year = "2005"
}