PT  - JOURNAL ARTICLE
AU  - W., M. M.
TI  - Looking for the Hard Background
AID  - 10.1126/science.251.4992.381
DP  - 1991 Jan 25
TA  - Science
PG  - 381--381
VI  - 251
IP  - 4992
4099  - http://science.sciencemag.org/content/251/4992/381.short
4100  - http://science.sciencemag.org/content/251/4992/381.full
SO  - Science1991 Jan 25; 251