The NASA Astrophysics Data System: Data holdings

Since its inception in 1993, the ADS Abstract Service has became an indispe nsable research tool for astronomers and astrophysicists worldwide. In thos e seven years, much effort has been directed toward improving both the quan tity and the quality of references ill the database. From the original data base of approximately 160 000 astronomy abstracts, our dataset has grown al most tenfold to approximately 1.5 million references covering astronomy, as trophysics, planetary sciences, physics, optics, and engineering. We collec t and standardize data. from approximately 200 journals and present the res ulting information in a uniform. coherent manner. With the cooperation of j ournal publishers worldwide, we have been able to place scans of full journ al articles on-line back to the first volumes of many astronomical journals , and we are able to link to current version of articles, abstracts, and da tasets for essentially all of the current astronomy literature. The trend t oward electronic publishing in the field, the use of electronic submission of abstracts for journal articles and conference proceedings, and the incre asingly prominent use of the World Wide Web to disseminate information have enabled the ADS to build a database unparalleled in other disciplines. The ADS can be accessed at: http://adswww.harvard.edu.