Alia I. Abdelmoty Norman W. Paton M. Howard Williams Alvaro A. A. Fernandes Maria L. Barja Andrew Dinn Geographic Data Handling in a Deductive Object-Oriented Database. 445-454 1994 conf/dexa/1994 DEXA db/conf/dexa/dexa94.html#AbdelmotyPWFBD94 http://dx.doi.org/10.1007/3-540-58435-8_209