MolluscaBase eds. (2025). MolluscaBase. Estonioceras imperfectum (Quenstedt, 1845) †. Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=1756186 on 2025-05-22
basis of recordKröger, B.; Mutvei, H. (2005). Nautiloids with multiple paired muscle scars from lower-middle Ordovician of Baltoscandia. <em>Palaeontology.</em> 48(4): 781-791., available online athttps://doi.org/10.1111/j.1475-4983.2005.00478.x page(s): 787 [details]