@misc{ordunamalea2014empirical,
  abstract = {The goal of this working paper is to summarize the main empirical evidences
provided by the scientific community as regards the comparison between the two
main citation based academic search engines: Google Scholar and Microsoft
Academic Search, paying special attention to the following issues: coverage,
correlations between journal rankings, and usage of these academic search
engines. Additionally, selfelaborated data is offered, which are intended to
provide current evidence about the popularity of these tools on the Web, by
measuring the number of rich files PDF, PPT and DOC in which these tools are
mentioned, the amount of external links that both products receive, and the
search queries frequency from Google Trends. The poor results obtained by MAS
led us to an unexpected and unnoticed discovery: Microsoft Academic Search is
outdated since 2013. Therefore, the second part of the working paper aims at
advancing some data demonstrating this lack of update. For this purpose we
gathered the number of total records indexed by Microsoft Academic Search since
2000. The data shows an abrupt drop in the number of documents indexed from
2,346,228 in 2010 to 8,147 in 2013 and 802 in 2014. This decrease is offered
according to 15 thematic areas as well. In view of these problems it seems
logical not only that Microsoft Academic Searchwas poorly used to search for
articles by academics and students, who mostly use Google or Google Scholar,
but virtually ignored by bibliometricians},
  author = {Orduna-Malea, Enrique and Ayllon, Juan Manuel and Martin-Martin, Alberto and Lopez-Cozar, Emilio Delgado},
  interhash = {4502aa3a64de2197a1a3724d2ed43f8d},
  intrahash = {ab883378446caed67ceb55ab219917ee},
  note = {cite arxiv:1404.7045Comment: 14 pages, 7 figures, 6 tables},
  title = {Empirical Evidences in Citation-Based Search Engines: Is Microsoft
  Academic Search dead?},
  url = {http://arxiv.org/abs/1404.7045},
  year = 2014
}

@misc{lpezczar2012manipulating,
  abstract = {The launch of Google Scholar Citations and Google Scholar Metrics may provoke
a revolution in the research evaluation field as it places within every
researchers reach tools that allow bibliometric measuring. In order to alert
the research community over how easily one can manipulate the data and
bibliometric indicators offered by Google s products we present an experiment
in which we manipulate the Google Citations profiles of a research group
through the creation of false documents that cite their documents, and
consequently, the journals in which they have published modifying their H
index. For this purpose we created six documents authored by a faked author and
we uploaded them to a researcher s personal website under the University of
Granadas domain. The result of the experiment meant an increase of 774
citations in 129 papers (six citations per paper) increasing the authors and
journals H index. We analyse the malicious effect this type of practices can
cause to Google Scholar Citations and Google Scholar Metrics. Finally, we
conclude with several deliberations over the effects these malpractices may
have and the lack of control tools these tools offer},
  author = {López-Cózar, Emilio Delgado and Robinson-García, Nicolás and Torres-Salinas, Daniel},
  interhash = {99886e72204cb2154bf6a0481e782bdd},
  intrahash = {18876648c3a45cd3ac5a3527a8fbdf44},
  note = {cite arxiv:1212.0638Comment: 10 pages, 4 figures},
  title = {Manipulating Google Scholar Citations and Google Scholar Metrics:
  simple, easy and tempting},
  url = {http://arxiv.org/abs/1212.0638},
  year = 2012
}