@article{Larsen:2010:Scientometrics:20700371,
  abstract = {The growth rate of scientific publication has been studied from 1907 to 2007 using available data from a number of literature databases, including Science Citation Index (SCI) and Social Sciences Citation Index (SSCI). Traditional scientific publishing, that is publication in peer-reviewed journals, is still increasing although there are big differences between fields. There are no indications that the growth rate has decreased in the last 50 years. At the same time publication using new channels, for example conference proceedings, open archives and home pages, is growing fast. The growth rate for SCI up to 2007 is smaller than for comparable databases. This means that SCI was covering a decreasing part of the traditional scientific literature. There are also clear indications that the coverage by SCI is especially low in some of the scientific areas with the highest growth rate, including computer science and engineering sciences. The role of conference proceedings, open access archives and publications published on the net is increasing, especially in scientific fields with high growth rates, but this has only partially been reflected in the databases. The new publication channels challenge the use of the big databases in measurements of scientific productivity or output and of the growth rate of science. Because of the declining coverage and this challenge it is problematic that SCI has been used and is used as the dominant source for science indicators based on publication and citation numbers. The limited data available for social sciences show that the growth rate in SSCI was remarkably low and indicate that the coverage by SSCI was declining over time. National Science Indicators from Thomson Reuters is based solely on SCI, SSCI and Arts and Humanities Citation Index (AHCI). Therefore the declining coverage of the citation databases problematizes the use of this source.},
  author = {Larsen, P O and von Ins, M},
  doi = {10.1007/s11192-010-0202-z},
  interhash = {cfb4b308f2ca153eaa7540b7d64b3577},
  intrahash = {abdc38dfe051e5b29c8742ab3b950b9c},
  journal = {Scientometrics},
  month = sep,
  number = 3,
  pages = {575-603},
  pmid = {20700371},
  title = {The rate of growth in scientific publication and the decline in coverage provided by Science Citation Index},
  url = {http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2909426/},
  volume = 84,
  year = 2010
}

@article{cattuto2007growth,
  abstract = {We analyze a large-scale snapshot of del.icio.us and investigate how the number of different tags in the system grows as a function of a suitably defined notion of time. We study the temporal evolution of the global vocabulary size, i.e. the number of distinct tags in the entire system, as well as the evolution of local vocabularies, that is the growth of the number of distinct tags used in the context of a given resource or user. In both cases, we find power-law behaviors with exponents smaller than one. Surprisingly, the observed growth behaviors are remarkably regular throughout the entire history of the system and across very different resources being bookmarked. Similar sub-linear laws of growth have been observed in written text, and this qualitative universality calls for an explanation and points in the direction of non-trivial cognitive processes in the complex interaction patterns characterizing collaborative tagging. },
  author = {Cattuto, Ciro and Baldassarri, Andrea and Servedio, Vito Domenico Pietro and Loreto, Vittorio},
  interhash = {7de017393b2d48335e209a9db23e08b6},
  intrahash = {04bc17658d8d028e01d69123b5dc6b40},
  journal = {CoRR},
  month = apr,
  note = {arXiv:0704.3316v1},
  title = {Vocabulary growth in collaborative tagging systems},
  url = {http://arxiv.org/abs/0704.3316},
  volume = {abs/0704.3316},
  year = 2007
}