Title: Barrier Pillars in the Western Middle Field: Anthracite Region of Pennsylvania
Author: Ash, S.H.
Additional Author: Kennedy, D.O.
Additional Author: et al

Date: 1953
Link to Full Report:
Document Type: USBM
Issuing Agency: U.S. Bureau of Mines
Performing Organization: U.S. Bureau of Mines

Report Number: USBM Bulletin 521
SUDOC: TN 23 U4
Series: U.S. Bureau of Mines Bulletins

Notes:
H.B. Link and W.M. Romischer