Reference over 5,000,000 compounds, atom by atom, bond bv b o n d . The QUESTEL service brings together two international scientific retrieval systems, QUESTEL and DARC, to provide the on-line user a new generation of reference systems for chemistry. In one session the systems permit the retrieval of structures a n d bibliographic information for over 5,000,000 c h e m i c a l compounds. DARC, the first and most fully developed on line structure search system available today, eliminates the ambiguity of codes a n d nomenclature by the use of graphic or alpha numeric input of structures. Each molecule can be described by a graph, the nature of the atoms and the type of bonds. DARC provides access to the EURECAS file which contains the entire Chemical Abstracts (CAS) Registry file. The CAS Registry numbers for the retrieved structures are automatically transferred to the QUESTEL bibliographic system. QUESTEL retrieves the literature of chemistry and other related sciences including patents from
26 countries. Bibliographic information can be searched not only by registry number but also by subject. The QUESTEL/DARC system is easy to learn. To assist you with your searching, QUESTEL offers comprehensive workshop training programs and quick re sponse technical -Τ—T\ support via our - -
