@inproceedings{1057760,
    title = "Characterization of the structures which admit effective enumerations",
    author = "Ditchev, Angel",
    year = "1999",
    pages = "92-96",
    booktitle = "Β' Πανελλήνιο Συμπόσιο Λογικής: πρακτικά"
}