The Dutch Tax and Customs Administration (DTCA) is one of many organizations that deal with a multitude of electronic legal data, from various sources and in different formats. In this paper, we describe the results of a study aimed at better access to these sources by having a supplier and format independent knowledge store that describes the sources and their interrelations in a semantic network. Furthermore we developed parsers to automatically detect the identity of sources and typed references within the sources to other legal documents. These parsers can be used to fill and update the semantic network as new documents are added. Categories and Subject Descriptors I.2.1 [Applications and Expert Systems]: Law; J.1 [Administrative processing]: Law. Keywords Semantic web, reference parsing, standardisation, legal CMS.