Chemical Patents Plus: FREE searching of all classes of fulltext U.S. patent documents from 1971,
Chemical Patents Plus offers FREE searching of all classes of the fulltext documents in the patent database of the U.S. Patent and Trademark Office (USPTO) from 1971 to the present, with only partial coverage from 1971-1974. Complete patent page images are available for all patents issued from 1 January 1994. Chemical Patents Plus includes CAS Registry Numbers and complete subject indexing for ...
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