2 literature references for Pneumodermopsis michaelsarsi Bonnevie, 1913:

Author: Spoel, Siebrecht van der
Year: 1976
Title:
Source: Pseudothecosomata, Gymnosomata and Heteropoda (Gastropoda)
Author: Spoel, Siebrecht van der, and José R. Dadon / Boltovskoy, Demetrio, ed.
Year: 1999
Title: Pteropoda
Source: South Antlantic Zooplankton, vol. 1