Manolis Marazakis Dimitris Papadakis Stavros A. Papadakis A Framework for the Encapsulation of Value-Added Services in Digital Objects. 75-94 http://link.springer.de/link/service/series/0558/bibs/1513/15130075.htm 1998 conf/ercimdl/1998 ECDL db/conf/ercimdl/ercimdl98.html#MarazakisPP98