Figure 2a from: Dimitrova M, Senderov VE, Georgiev T, Zhelezov G, Penev L (2021) Infrastructure and Population of the OpenBiodiv Biodiversity Knowledge Graph. Biodiversity Data Journal 9: e67671. https://doi.org/10.3897/BDJ.9.e67671 - Dimitrova, Mariya (2021)