TY  - BOOK
AU  - "United Nations, Government Of ... Economic Commission For Europe, Secretariat"
ED  - "United Nations, Government Of ... Economic Commission For Europe, Secretariat"
TI  - "International classification of hard, coals by type"
U1  - "F551:91, J6/UN" 
PY  - 1956///
CY  - Geneva
PB  - United Nations      
KW  - Technology
ER  -