Conodonts from the Lower Ordovician of Morocco - contributions to age and faunal diversity of the Fezouata Lagerstätte and peri-Gondwana biogeographyLehnert, Oliver; Nowak, Hendrik; Sarmiento, Graciela N.; Gutierrez-Marco, Juan Carlos; Akodad, Mustapha; Servais, ThomasPalaeogeography, palaeoclimatology, palaeoecology2016 / p. 50-61 : ill https://doi.org/10.1016/j.palaeo.2016.03.023 Journal metrics at Scopus Article at Scopus Journal metrics at WOS Article at WOS

High-resolution trilobite stratigraphy of the Lower–Middle Ordovician Öland Series of BaltoscandiaPärnaste, Helje; Bergström, Jan; Zhiyi, ZhouGeological magazine2013 / p. 509-518 : ill https://pubs.geoscienceworld.org/geolmag/article-abstract/150/3/509/299539/High-resolution-trilobite-stratigraphy-of-the https://doi.org/10.1017/S0016756812000908 Journal metrics at Scopus Article at Scopus Journal metrics at WOS Article at WOS

Lower and Middle Ordovician conodonts from the subsurface of SE Estonia and adjacent RussiaViira, ViiveEstonian journal of earth sciences2011 / 1, p. 1-21 : ill https://artiklid.elnet.ee/record=b2284309*est

Lower Ordovitsian Leetse Formation in the North Estonian Klint areaViira, Viive; Mens, Kaisa; Nemliher, JüriProceedings of the Estonian Academy of Sciences. Geology2006 / 2, p. 156-174 : ill