Landslides in Pennsylvania / by Helen L. Delano and J. Peter Wilshusen. 2nd ed.

Chicago citation style
Delano, Helen L. Landslides in Pennsylvania / by Helen L. Delano and J. Peter Wilshusen. 2nd ed.. Retrieved from the Digital Public Library of America, https://archive.org/details/landslidesinpenn00dela_0. (Accessed December 14, 2018.)
APA citation style
Delano, Helen L, Landslides in Pennsylvania / by Helen L. Delano and J. Peter Wilshusen. 2nd ed.. Retrieved from the Digital Public Library of America, https://archive.org/details/landslidesinpenn00dela_0
MLA citation style
Delano, Helen L. Retrieved from the Digital Public Library of America <https://archive.org/details/landslidesinpenn00dela_0>.
Note: These citations are programmatically generated and may be incomplete.