Correlation of upper Llandovery-lower Wenlock bentonites in the När (Gotland, Sweden) and Ventspils (Latvia) drill cores: role of volcanic ash clouds and shelf sea currents in determining areal distribution of bentoniteKiipli, Tarmo; Kallaste, Toivo; Nestor, Viiu-KaiEstonian journal of earth sciences2012 / p. 295-306 : ill https://www.researchgate.net/publication/259465427_Correlation_of_upper_Llandovery-lower_Wenlock_bentonites_in_the_Nar_Gotland_Sweden_and_Ventspils_Latvia_drill_cores_Role_of_volcanic_ash_clouds_and_shelf_sea_currents_in_determining_areal_distribution

Geochemical discimination of the Upper Ordovician Kinnekulle Bentonite in the Billegrav-2 drill core section, Bornholm, DenmarkKiipli, Tarmo; Kallaste, Toivo; Nielsen, Arne T.; Schovsbo, Niels H.; Siir, SvenEstonian journal of earth sciences2014 / p. 264-270 : ill https://artiklid.elnet.ee/record=b2705908*est

Immobile and mobile elements during the transition of volcanic ash to bentonite - an example from the early Palaeozoic sedimentary section of the Baltic BasinKiipli, Tarmo; Hints, Rutt; Kallaste, Toivo; Verš, Evelin; Voolma, MargusSedimentary geology2017 / p. 148-159 : ill https://doi.org/10.1016/j.sedgeo.2016.11.009

Silurian bentonites in Lithuania : correlations based on sanidine phenocryst composition and graptolite biozonation - interpretation of volcanic source regionsKiipli, Tarmo; Radzevičius, Sigitas; Kallaste, ToivoEstonian journal of earth sciences2014 / p. 18-29 : ill https://artiklid.elnet.ee/record=b2663120*est