Direct evidence for R- rotons having antiparallel momentum and velocity   [electronic resource] 

 -  Science (New York, N.Y.)  Feb 1999 
 - 1150-2 p.  digital 
<br/><br/> Publication Type: Journal Article 
<br/><br/><label>ISSN: </label>1095-9203 
<br/><br/><label>Standard No.: </label>10.1126/science.283.5405.1150  doi