Hayward, B.W.; Le Coze, F.; Gross, O. (2018). World Foraminifera Database.
Sigmoilopsis Finlay, 1947. Accessed through: Glover, A.G., Higgs, N., Horton, T. (2018) World Register of Deep-Sea species (WoRDSS) at: http://www.marinespecies.org/deepsea/aphia.php?p=taxdetails&id=112044 on 2018-04-26
Glover, A.G., Higgs, N., Horton, T. (2018). World Register of Deep-Sea species (WoRDSS).
Sigmoilopsis Finlay, 1947. Accessed at: http://www.marinespecies.org/deepsea/aphia.php?p=taxdetails&id=112044 on 2018-04-26