Pennsylvania geology.
Pennsylvania.Bureau of Topographic and Geologic Survey.
[Harrisburg] : [Topographic and Geologic Survey, Dept. of Environmental Resources]
Vol. 1, 1969-70 has 9 bimonthly issues.
Vol. 5/2 numbered incorrectly as v. 2/5.
Mode of access: World Wide Web.
Description based on print version record.
Latest issue consulted: Vol. 43, no. 3 (fall 2013) (Pennsylvania Geological Survey website, viewed January 2, 2014).
Geology
Geology.