• The Ordovician System in EstoniaMeidla, Tõnu; Ainsaar, Leho; Hints, OlleThe Seventh Baltic Stratigraphical Conference : 17-18 May 2008, Tallinn, Estonia : abstracts & field guide2008 / p. 95-98 : ill
• The Ordovician system in EstoniaMeidla, Tõnu; Ainsaar, Leho; Hints, OlleXI Baltic Stratigraphical Conference : abstracts and field guide2024 / p. 54-59 : ill https://www.ester.ee/record=b5696260*est https://kirjandus.geoloogia.info/en/reference/49701