Frequency of papers showing academic misconduct among the articles indexed by MathSciNet and Zentralblatt MATH Among the papers indexed by MathSciNet and Zentralblatt MATH,
I occasionally have seen papers which consist essentially only
of text copied from elsewhere without proper attribution and without
adding any significant value. I would be interested whether anyone
has an idea what the frequency of such papers among those indexed in
the mentioned databases roughly is. --
Are these extremely rare cases, or are such papers more common than one usually thinks, and perhaps even not easy to keep out of the databases if
one doesn't want to be too restrictive in which journals to cover? --
Is there any data known on this?
Also, if one spots such a paper -- should one report this to the
authors or copyright holders of the pieces of text from which the 
paper is composed, to the editorial board of the journal in which 
the paper is published, or to MathSciNet / Zentralblatt MATH --
or rather just ignore it? What is common practice in such case?
 A: What you should do about it: (1) Decide if the case is blatant enough that action is demanded. There are many borderline cases where a previous paper is attributed but not adequately; probably they are not worth bothering about. (2) Send both papers to the editor of the journal which published the second paper, with a covering letter spelling out what copying has been done that you believe is unacceptable.  Include a CC to the author of the first paper.  A CC to the editor who published the first paper is optional.  No CC to the plagiarist is needed; the editor of the second paper will take care of that if he/she decides to act.
A: On behalf of zbMATH (which is certainly also the case for MathSciNet), we would very much appreciate a notification of such cases, if they have not yet been detected at the level of editors or reviewers. There is the general impression of our editors (which has been discussed with our MathSciNet colleagues who seem to share this) that this behaviour has become significantly more widespread recently, and that such papers make it frequently into journals which usually have shown a level of decent peer review (which should generally filter such submissions).
The notification could either be done by an email to editor@zbmath.org or to volunteer to write a short review about this case https://zbmath.org/become-a-reviewer/.
We would then evaluate the level of copying and 
1) Inform the editorial board,
2) our colleagues of MathSciNet,
3) Add a review or editorial remark mentioning the degree of overlap, ideally taking into account statements of the editorial board and, possibly, the author(s) if provided.
We do not display automated warnings like on arXiv because all existing tools (known to us) produce too many false positives when applied to math content, which seem unsatisfactory for public statements (e.g., arXiv claims overlap for arXiv:1609.02231 and arXiv:1412.0555 where the same problem is considered for genus three and even genus).
Searching for "plagiarism" will not result in all cases, because that means that intention and priority has been clearly identified, which is not always clear especially when things are under investigation (indeed, we had various cases where the paper which was published, or even submitted, first turned out to be a copy of ongoing unpublished other work published later). Hence, the documents will be usually labeled as "identical", "almost identical", "parts are almost identical" etc. - the results https://zbmath.org/?t=&s=0&q=%28%28%22reviewer%27s+remark%22%7C+%22editorial+remark%22%29+%26+%28identical+%7C+plagiarism%29 may give an impression.
Olaf Teschke, Managing Editor, zbMATH
A: On behalf of MathSciNet / Mathematical Reviews, I concur with Olaf Teschke that we appreciate notification of such cases.  We too sense that the number of cases has increased.  The majority of the alerts we receive come from our reviewers.  We sometimes have authors contact us to say that their papers have been republished by someone else.  And we do receive a number of notifications from third parties.  
If you wish to notify MathSciNet of such a case, you may write to mrexec@ams.org (as in MR Executive Editor). If you wish to become a reviewer, you may write to us at mathrev@ams.org.  
As with zbMATH, when a case of duplicated text or duplicated papers comes up, we contact the editorial boards of both journals, inform the editors at zbMATH, and add a note to the listing of the paper.  
Edward Dunne, 
Executive Editor, 
Mathematical Reviews
