More than 2 million species have been described since Carl von Linné founded biological taxonomy in 1753. The descriptions of these species use an estimated 500 million pages, of which about 50 million pages have been digitized in the Biodiversity Heritage Library (BHL) and other sites such as JSTOR. However, species are not just described — they are redescribed and redefined, split into multiple species, or multiple species are merged into one, all documented in scientific publications. Hence our understanding of species constantly changes. In other words, descriptions go through versions that need to be stored and linked to each other via citations which help scientists to constantly track and update this knowledge.