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Searching the Cited Derwent Primary Accession Number Field

Searches the Derwent Primary Accession Number field within a cited patent record.

Enter one or more Primary Accession Numbers connected with the OR or NOT search operators. You can enter a complete Primary Accession Number or a partial Primary Accession Number using wildcards.

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About the Derwent Primary Accession Number

The Primary Accession Number is a unique identification number assigned by Derwent to each document. It consists of the following:

• year of publication,
• a six-digit serial number, and
• a two-digit update number indicating when Derwent published the patent abstract.

To search for a patent using the Primary Accession Number, enter the four-digit year, a hyphen, and then the six-digit serial number.

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Search Example

1995-132765 finds patent records that cite this particular patent.