Hayward, B.W., Kawagata, S., Sabaa, A.T., Grenfell, H.R., van Kerckhoven, L., Johnson, K., and Thomas, E., 2012. The last global extinction (Mid-Pleistocene) of deep-sea benthic foraminifera (Chrysalogoniidae, Ellipsoidinidae, Glandulonodosariidae, Plectofrondiculariidae, Pleursostomellidae, Stilostomellidae), their Late Cretaceous-Cenozoic history and taxonomy: Cushman Foundation for Foraminiferal Research Special Publication, v. 43, pl. 29, fig 30. North Atlantic, early Pleistocene
Hayward, B.W., Kawagata, S., Sabaa, A.T., Grenfell, H.R., van Kerckhoven, L., Johnson, K., and Thomas, E., 2012. The last global extinction (Mid-Pleistocene) of deep-sea benthic foraminifera (Chrysalogoniidae, Ellipsoidinidae, Glandulonodosariidae, Plectofrondiculariidae, Pleursostomellidae, Stilostomellidae), their Late Cretaceous-Cenozoic history and taxonomy: Cushman Foundation for Foraminiferal Research Special Publication, v. 43, pl. 29, figs 28-29. North Atlantic, early Pleistocene