Chitinozoan biostratigraphy in the Haljala Regional Stage, Upper Ordovician: A high-resolution approach from NE EstoniaBauert, Garmen; Nõlvak, Jaak; Bauert, HeikkiGFF2014 / p. 26-29 : ill https://doi.org/10.1080/11035897.2013.857715 Journal metrics at Scopus Article at Scopus Journal metrics at WOS Article at WOS The lower boundary of the Haljala Regional Stage (Sandbian, Upper Ordovician) in EstoniaPaiste, Tõnn; Männik, Peep; Nõlvak, Jaak; Meidla, TõnuEstonian journal of earth sciences2020 / p. 76–90 : ill https://doi.org/10.3176/earth.2020.05 Journal metrics at Scopus Article at Scopus Journal metrics at WOS Article at WOS