Pfefferkorn, H. W., Peppers, R. A., & Phillips, T. L. (1971). Some fern-like fructifications and their spores from the Mazon Creek compression flora of Illinois (Pennsylvanian).
Chicago-Zitierstil (17. Ausg.)Pfefferkorn, Hermann W., Russel Allen Peppers, und Tom Lee Phillips. Some Fern-like Fructifications and Their Spores from the Mazon Creek Compression Flora of Illinois (Pennsylvanian). Urbana, Ill, 1971.
MLA-Zitierstil (9. Ausg.)Pfefferkorn, Hermann W., et al. Some Fern-like Fructifications and Their Spores from the Mazon Creek Compression Flora of Illinois (Pennsylvanian). 1971.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.