Revision of Psammosteus livonicus Obruchev (Agnatha, Heterostraci) from the Devonian Amata regional stage of the NW of the East European platformGlinskiy, Vadim N.; Mark-Kurik, ElgaEstonian journal of earth sciences2016 / p. 1-18 : ill 10.3176/earth.2016.02 Silurian cyathaspidid heterostracans of Northern EurasiaMärss, TiiuEstonian journal of earth sciences2019 / p. 113–146 : ill https://doi.org/10.3176/earth.2019.11 https://www.ester.ee/record=b2246661*est Journal metrics at Scopus Article at Scopus Journal metrics at WOS Article at WOS