TY  - JOUR
PB  - American Physical Society
ID  - 10.1103/PhysRevFocus.24.9
TI  - What Makes It So Hard?
JF  - Physical Review Focus
JA  - Phys. Rev. Focus
J1  - FOCUS
VL  - 24
IS  - 
SP  - 9
EP  - 
PY  - 2009/09/04/
UR  - http://link.aps.org/doi/10.1103/PhysRevFocus.24.9
A1  - Monroe, Don
ER  -