Kozłowska, A., Bates, D., Zalasiewicz, J. & Radzevičius, S. (2019) Evolutionary significance of the retiolitine Gothograptus (Graptolithina) with four new species from the Silurian of the East European Platform (Baltica), Poland and Lithuania . Zootaxa, 4568 (3), 435–469.
https://doi.org/10.11646/zootaxa.4568.3.2