TY  - BOOK
AU  - Virgin,R.Z.
ED  - United States.
TI  - Coal-mine ventilation
T2  - Bulletin / Federal Board for Vocational Education
AV  - LC1045 .A25 no. 41
PY  - 1920///
CY  - Washington, D.C.
PB  - Federal Board for Vocational Education, Govt. Print. Off.
KW  - Mine ventilation
N1  - Cover title; "Prepared by R.Z. Virgin"--P. 5; "November, 1919."
ER  -