At: Arbeiten aus dem Institut für Paläobotanik und Petrographie der Brennsteine, 4 By: Wicher C. A.
bookAt: Sporenf. Aegirhoriz. Ruhr-Reviers, Würzburg, Dissertationsdruckerei K. Triltsch By: Ibrahim A. C.
journalAt: Paläontologische Abhandlungen, Abtheilung, B, Paläobotanik, 2, 3 By: Schulz E.
journalAt: Abhandlungen des Zentralen Geologischen Instituts, 18 By: Krutzsch W., Mibus I.
journalAt: Geologica Bavarica, 46 By: Wolf M.
journalAt: Commonwealth Scientific and Industrial Research Organisation Division of Coal Research Technical Communication, 25 By: Balme B. E.
bookAt: Rept. XVII Inter. Geol. Congr. 1937, Moscow, GONTI, 1 By: Naumova S. N.
journalAt: Transactions of the Illinois State Academy of Science, 28, 2 By: Schopf J. M.
journalAt: Acta botanica Academiae Scientiarum Hungaricae, 12, 1–2 By: Bóna J.
journalAt: Report of investigations Illinois State Geological Survey, 50 By: Schopf J. M.