Dirk Beyer Andreas Noack Claus Lewerentz Simple and Efficient Relational Querying of Software Structures. 216-225 2003 conf/wcre/2003 WCRE http://csdl.computer.org/comp/proceedings/wcre/2003/2027/00/20270216abs.htm db/conf/wcre/wcre2003.html#BeyerNL03