1. Reference Manager Research Information Systems 1991 Village Park Way Suite 206 Encinitas CA 92024.
2. Scholar's Bibliofile The Library Corporation P.O. Box 40601 Washington DC 20016.
3. Ref-11 DG Systems 322 Prospect Avenue Hartford CI 06106.
4. Pro-Cite Personal Bibliographyc Software P.O. Box 4250 Ann Arbor MI 48106.
5. Sci-Mate, Institute for Scientific Information, 3501 Market Street, Philadelphia , PA 1910 4 .