1. Solid modeling: A historical summary and contemporary assessment;Requicha;IEEE Computer Graphics Appl.,1982
2. Digital representation for communication of product definition data;ANSI,1981
3. Format zum Austausch geometrischer Informationen;DIN,1986
4. Representation externe des donnees de definition de produits, Specification du standard d'echange et de transfert (SET);AFNOR;Norme Experimentale Z 68–300,1985
5. Representations for rigid solids: Theory methods, and systems;Requicha;ACM Comp. Surveys,1980