Aguilar, M Precision Measurement of the Helium Flux in Primary Cosmic Rays of Rigidities 1.9 GV to 3 TV with the Alpha Magnetic Spectrometer on the International Space Station. [electronic resource] - Physical review letters Nov 2015 - 211101 p. digital Publication Type: Journal Article ISSN: 1079-7114 Standard No.: 10.1103/PhysRevLett.115.211101 doi