1. Object‐oriented database management systems for engineering: A comparison;Ahmed S.;Journal of Object‐Oriented Programming,1992
2. BoudierC. C.Cuisinier F.Bruno U.Kelter W.Seelbach D.Nolte F.Stewing D.Mulcahy &D.O'Riordan.Implementing PCTE on an Object‐Oriented Database. InProceedings of PCTE '94 1994.