@TECHREPORT\{IMM1996-01865,
    author       = "A. E. Haxthausen and F. Nickl",
    title        = "Pushouts of Order-sorted Algebraic Specifications",
    year         = "1996",
    number       = "",
    series       = "",
    institution  = "Institut für Informatik, Ludwig-Maximilians-Universit{\"{a}}t München",
    address      = "",
    type         = "",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/1865-full.html",
    isbn_issn    = "Technischer Bericht 9601"
}