@misc{Halpin2005,
    title = {{ORM 2 Graphical Notation}},
    author = {Terry Halpin},
    institution = {Neumont University},
    number = 1,
    year = 2005,
    url = {http://www.orm.net/pdf/ORM2_TechReport1.pdf}
}
@book{Halpin2008,
    title = {Information Modeling and Relational Databases},
    author = {Terry Halpin and Tony Morgan},
    isbn = {978-0-12-373568-3},
    publisher = {Morgan Kaufmann},
    year = 2008,
    description = {2nd edition}
}
@misc{GPL2,
    title = {{GNU Public License Version 2}},
    publisher = {Free Software Foundation},
    year = 1991,
}
@misc{LPPL,
    title = {{LaTeX Project Public License (LPPL) Version 1.3c}},
    publisher = {LaTeX3 Project},
    year = 2008,
}