PT  - JOURNAL ARTICLE
ED  - , 
TI  - WORLD PRODUCTION OF COAL IN 1920
AID  - 10.1126/science.53.1375.431-a
DP  - 1921 May 06
TA  - Science
PG  - 431--432
VI  - 53
IP  - 1375
4099  - http://science.sciencemag.org/content/53/1375/431.2.short
4100  - http://science.sciencemag.org/content/53/1375/431.2.full
SO  - Science1921 May 06; 53