Hypertext systems are being used in many applications because of their flexible structure and the great browsing freedom they give to diverse communities of users. However, this same freedom and flexibility is the cause of one of its main problem: the " lost in hyperspace" problem. One reason for the complexity of hypertext databases is the large number of nodes and links that compose them. To simplify this structure we propose that nodes and links be clustered forming more abstract structures. An abs traction is the concealment of all but relevant properties from an object or concept. One type of abstraction is called an aggregate. An aggregate is a set of distinct concepts that taken together form a more abstract concept. For example, two legs, a trunk, two arms and a head can be aggregate together in a single higher level object called a "body." In this paper we will study the hypertext structure, i.e., the way nodes are linked to each other in order to find aggregates in hypertext databases. T wo graph theoretical algorithms will be used: biconnected components and strongly connected components.