Hayward, B.W.; Le Coze, F.; Vachard, D.; Gross, O. (2021). World Foraminifera Database. Robulus expansus var. planulatus (Cushman, 1917). Accessed at: http://www.marinespecies.org/foraminifera/aphia.php?p=taxdetails&id=710640 on 2024-06-19
new combination referenceCushman, J. A. (1933). The Foraminifera of the tropical Pacific collections of the "Albatross," 1899-1900. Pt. 2. Lagenidae to Alveolinellidae. <em>Bulletin of the United States National Museum.</em> 161(2): 1-79 + pls., available online athttps://www.biodiversitylibrary.org/page/7692388[details]