Suad Alagic Tuong Nguyen Parametric Polymorphism and Orthogonal Persistence. 32-46 http://link.springer.de/link/service/series/0558/bibs/1944/19440032.htm 2000 conf/oodbs/2000 Objects and Databases db/conf/oodbs/oodbs2000.html#AlagicN00