@PHDTHESIS\{IMM1988-01853,
    author       = "A. E. Haxthausen",
    title        = "Structuring Mechanisms in Formal Specification Languages",
    year         = "1988",
    school       = "Department of Computer Science,   Technical University of Denmark",
    address      = "",
    type         = "",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/1853-full.html",
    isbn_issn    = "ID-TR:1988-42"
}