Hall, C. E. (1881). The geology of Philadelphia County and of the southern parts of Montgomery and Bucks. Board of Commissioners for the Second Geological Survey.
Chicago-Zitierstil (17. Ausg.)Hall, Charles E. The Geology of Philadelphia County and of the Southern Parts of Montgomery and Bucks. Harrisburg: Board of Commissioners for the Second Geological Survey, 1881.
MLA-Zitierstil (9. Ausg.)Hall, Charles E. The Geology of Philadelphia County and of the Southern Parts of Montgomery and Bucks. Board of Commissioners for the Second Geological Survey, 1881.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.