TY  - GEN
TI  - Direct evidence for R- rotons having antiparallel momentum and velocity 
SN  - 1095-9203
PY  - 1999///
PB  - Science (New York, N.Y.)
N1  - Publication Type: Journal Article
UR  - https://doi.org/10.1126/science.283.5405.1150
ER  -