@CONFERENCE\{IMM1983-01585,
    author       = "H. Riis Nielson",
    title        = "Proof Systems for Computation Time",
    year         = "1983",
    booktitle    = "Proc. Third Conference on Foundations of Software Technology and Theoretical Computer Science",
    volume       = "",
    series       = "",
    editor       = "",
    publisher    = "",
    organization = "",
    address      = "",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/1585-full.html"
}