The Pennsylvania geological survey;
administrative report,
by Geo. H. Ashley.
APA Citation
Pennsylvania. Bureau of Topographic and Geologic Survey., Ashley, G. H. (George Hall). (1931). The Pennsylvania geological survey: administrative report. Harrisburg, Pa.: Dept. of internal affairs, Topographic and geologic survey.
MLA Citation
Pennsylvania. Bureau of Topographic and Geologic Survey, and Geo. H. (George Hall) Ashley. The Pennsylvania Geological Survey: Administrative Report. Harrisburg, Pa.: Dept. of internal affairs, Topographic and geologic survey, 1931.
Warning: These citations may not always be complete (especially for serials).