CLOG: A Class-Based Logic Language for Object-Oriented Databases. - Siu Cheung Hui; Angela Goh; Jose Kolencheril Raphel (ISOTAS, 1993)

Class based contextual logic for DOOD. - Jose Kolencheril Raphel; Siu Cheung Hui; Angela Goh (J. Comput. Sci. Technol., 1996)