Citation Database Help Topics

Reference lists in MathSciNet
The Citation Database Reference Journals List
Matched references in reference lists
Select an author
Author information returned from the Citation Database
Select a journal
Journal information returned from the Citation Database
Understanding the Citation Database

Reference lists in MathSciNet

The MR Database includes reference lists from selected journals. These reference lists are, in all cases, taken from issues published from 2000 to the present and in certain cases from issues published from 1997 to the present. Most of the reference lists are keyboarded from the original paper. In the case of a few journals a method of automated extraction is used. In both cases, the resulting reference lists are run though an automated matching algorithm to match as many references as possible to items in the MR Database.

The reference lists are presented following the review text associated with the item. No attempt is made in keyboarding to correct errors in reference lists. They are presented exactly as they appear in the original paper.

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The Citation Database Reference List Journals

The Citation Database is based on the information contained in reference lists drawn from certain journals covered by MathSciNet. Reference lists in all of the journals covered in the Citation Database go back to a publication year of 2000. A smaller number of journals have reference lists in MathSciNet back to 1997. A careful process of editorial selection goes into the construction of the Citation Database journal list.

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Matched references in reference lists

In order to provide the highest level of accuracy in the Citation Database, all items in MathSciNet reference lists are matched to the MR Database in an automated process. Only those citations that unambiguously match to an item in the Database are included in the Citation Database. These matchings are noted explicitly, in any particular reference list, by the resulting MathSciNet link. The bibliographic information for a matched item used in the Citation Database is taken from the MR Database, not from the reference list text, which is always taken verbatim from the original item.

There are several reasons why a particular reference list citation may not match with a MathSciNet item, and thus be excluded from the Citation Database.

The citation may refer to an item that is not in the MR Database
This is the most typical reason. The publication date of the item may be earlier than the beginning of the MR Database, or the item may be in an area that is at the edge of coverage, or the item may be a preprint/submitted/in press item that has not yet been published.

The citation may have insufficient bibliographic information for confirming a match
In order to reduce the number of false positive matches, a certain level of confirmation is required by the automated procedures. Some journals use reference styles that omit titles, for example, and this frequently means that there is not enough confirming information to make a match.

The citation may have incorrect bibliographic information for confirming a match
The level of confirmation described in the preceding paragraph can also be subverted by incorrect information. For example, the wrong publication year can in some cases prevent a match.

The citation may be similar to more than one item in the MR Database
The matching algorithm has been very carefully tuned over time to both maximize the number of correct matches and minimize the number of incorrect matches. However, these ideals compete with each other. Monographs in multiple editions and continuation papers with the same title (I., II., etc.) can fail to match.

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Select an author

Authors in the Citation Database are selected in a manner very similar to the selection of authors in the MathSciNet Author Database. Names are entered last name first. If there is ambiguity, a list of authors is presented. Choose the desired author from the list.

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Author information returned from the Citation Database

The citation counts for the ten most frequently matched references associated with the author are given. These counts are over all MathSciNet reference lists. Because the MathSciNet reference list journals are only a portion of all journals covered by MathSciNet, these counts will typically be undercounts of the total number of references in the published mathematical literature. One reference list may contain several citations to a given author: these are all counted. The counts for each item are the Reference Citations counts for that item in MathSciNet.

If there are more than ten matched items associated with the author, the remaining number of matched references is given as a single total.

The count of all distinct authors whose citations are included in the total count is given at the top of the page. These authors are drawn from the MathSciNet author database, based on the matched items in MathSciNet reference lists.

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Select a journal

Journals in the Citation Database are selected in a manner very similar to the selection of journals in the MathSciNet Journal Search. You may enter the full journal name, the MathSciNet abbreviation, or in many cases almost any reasonable abbreviation. In some cases under specifying a journal name may be more successful than over specifying. If there is ambiguity, a list of journals is presented in a pull down menu. You may also enter an ISSN.

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Journal information returned from the Citation Database

Mathematical Citation Quotient
The Mathematical Citation Quotient compares two counts for a selected journal and a selected year. The first count is the number of matched references to papers in the given journal, from the selected publication year, over all reference list journals, where the references are within the five-year period preceding the given year. The second count is the total number of papers (indexed in MathSciNet) in the given journal over the same five-year period. The MCQ is the quotient, with the number of citations in the numerator and the number of papers in the denominator. The numbers of citations and numbers of papers are broken down for each year of the five-year period.

Example:

The journal in this example had a total of 592 items indexed in MathSciNet over the 5-year period from 1999 to 2003. Over all the reference lists in MathSciNet for issues with publication year 2004, there were a total of 259 matched references to papers in the given journal with publication year in the same 5-year period. The MCQ is the quotient of 259 and 592, namely .438.

The "35" in the top row of the table counts 35 matched references in reference list journals with publication year 2004 to papers in the selected journal with publication year 2003. The "104" in the top row counts 104 papers in the selected journal, with publication year 2003, indexed in MathSciNet.

The numbers in the Citations to Journal column link to headline lists of the MathSciNet items with the corresponding references in their associated reference lists. The numbers in the Published in Journal column link to the MathSciNet items for the journal articles in the given years.

The All Journal MCQ is given below the table for comparision purposes. This collapses all journals in the Citation Database into a single super-journal and calculates the MCQ for this All Journal journal, for the selected year.

Below the MCQ table, the counts of all references to the selected journal in the given year, by year of reference, are presented graphically, in 5 year intervals. In addition, the total number of matched references in the Citation Database to articles in the given journal, over all publication years, is given.

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Understanding the Citation Database

All the results returned by queries to the Citation Database should be interpreted with care.

• They are based on the reference lists in the restricted list of MathSciNet reference list journals: those journals for which a reference list is included in MathSciNet.
• The reference lists are a fairly new addition to the content of MathSciNet. A few of reference list journals include lists that go back to 1997, but for the majority of reference list journals, the reference lists begin with 2000.
• All counts are based on matching reference list items with the MR Database. Unmatched reference list entries are not included in any count.
• There can be false matches: citations that correspond to an item in the MR Database, but which match to another item in the MR Database. In these very few cases the item entered into the Citation Database is not the correct citation.

More information about the Citation Database can be found in the essay, Understanding the Citation Database.

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