Agenda 21 suggests that competent intergovernmental and non-governmental organizations could cooperate to provide governments and legislators, upon request, with an integrated programme of environment and development law (sustainable development law) services, carefully adapted to the specific requirements of recipient legal and administrative systems. Such systems could usefully include assistance in the preparation of comprehensive inventories and reviews of national legal systems. Past experience has demonstrated the usefulness of combining specialized legal information services with legal expert advice. Within the UN system, closer cooperation between all agencies concerned would avoid duplication of databases and facilitate division of labour. These agencies could examine the possibility and merit of performing reviews of selected national legal systems.