Relative pressure changes in coal pillars during extraction :
a progress report /
by Ernest A. Curth.

APA Citation

Curth, E. A. (1967). Relative pressure changes in coal pillars during extraction: a progress report. [Washington, D.C.]: U.S. Dept. of the Interior, Bureau of Mines.

MLA Citation

Curth, Ernest A. Relative Pressure Changes In Coal Pillars During Extraction: a Progress Report. [Washington, D.C.]: U.S. Dept. of the Interior, Bureau of Mines, 1967.

Warning: These citations may not always be complete (especially for serials).