• Lower to middle Ordovician trilobite faunas along the Ural border of BalticaPärnaste, Helje; Bergström, JanBulletin of Geosciences2014 / p. 431 - 450 https://doi.org/10.3140/bull.geosci.1448 https://www.scopus.com/sourceid/63670 https://www.scopus.com/record/display.uri?eid=2-s2.0-84901287882&origin=resultslist&sort=plf-f&src=s&sot=b&sdt=b&s=DOI%2810.3140%2Fbull.geosci.1448%29&sessionSearchId=56b7ce5a14becbdd2a7cedba4ac1cb4a&relpos=0 https://jcr.clarivate.com/jcr-jp/journal-profile?journal=B%20GEOSCI&year=2014 https://www.webofscience.com/wos/woscc/full-record/WOS:000336622700019
• Trilobites and biofacies in the Early-Middle Ordovician of Baltica and a brief comparison with the Yangtze PlateBergström, Jan; Pärnaste, Helje; Zhiyi, ZhouEstonian journal of earth sciences2013 / p. 205-230 : ill https://artiklid.elnet.ee/record=b2651566*est https://doi.org/10.3176/earth.2013.16 https://www.scopus.com/sourceid/6000195392 https://www.scopus.com/record/display.uri?eid=2-s2.0-84885847638&origin=resultslist&sort=plf-f&src=s&sot=b&sdt=b&s=DOI%2810.3176%2Fearth.2013.16%29&sessionSearchId=f5537800810c8e1f4bbc115ea06ecda6 https://jcr.clarivate.com/jcr-jp/journal-profile?journal=EST%20J%20EARTH%20SCI&year=2013 https://www.webofscience.com/wos/woscc/full-record/WOS:000327822600002