@inproceedings{
    bm1,
    author = "Back, R.J.R. and Mannila, Heikki",
    publisher = "Springer-Verlag",
    title = "Locality in modular systems",
    booktitle = "Proceedings of the Ninth International Colloquium on Automata, Languages and Programming",
    editors = "M. Nielsen and E.M. Schmidt",
    year = "1982",
    pages = "1-13"
}