Q:  I am browsing a printed issue or index of Chemical Abstracts, and I found a CA abstract number.  How do I find the reference associated with that abstract number on STN and SciFinder?

A:  The format of CA abstract numbers has changed over time.  As a result, the methods used to find these references using SciFinder and STN will vary.

CA Abstract Numbers for references from 1967-present:

  • Unique
  • Include the volume of CA followed by a colon and abstract number with a check digit. Example: 151:24562c

Searching and displaying CA Abstract Numbers from 1967-present:


Method STN SciFinder
Search Omit the check digit and search in the Document Number field.

S 151:245626/DN

Explore references by document identifier: 151:245626
Display AN   2009:845525  CAPLUS
DN   151:245626
Accession Number
CAN 151:245626

CA Abstract Numbers for references prior to 1967:

  • Not unique
  • Include the volume of CA followed by a colon and column number and column fraction letter representing the position of the abstract on the printed page. Example:  65:3705e

Searching and displaying CA Abstract Numbers prior to 1967:


Method STN SciFinder
Search Search in the /OREF (Original Reference) field.

S 65:3705E/OREF

Explore references only by document identifier: 65:20186

Cannot explore using CA reference numbers.

Display AN   1966:420186  CAPLUS
DN   65:20186
OREF 65:3705e-f
Accession Number
CAN 65:20186


Q:  Can I dispose of my Chemical Abstracts Print collection?

A:  While CAS cannot recommend to former CA Print customers what to do with your printed collections, we would like to provide you with any details necessary to make an informed decision. When determining whether to retain all or part of your CA Print collection, consider the kind of usage your CA Print gets, as well as your current and future access to other CAS products such as SciFinder or STN.  All information found in CA Print is available in its entirety in CA/CAplus, which can be accessed through either STN or SciFinder.


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