Julienne, Paul S.Leo, Paul J.Mies, Fred H.Williams, Carl J.2004-12-272004-12-2720012001http://hdl.handle.net/2003/1945910.17877/DE290R-12395enThe American Physical SocietyPhysical Review Letters530Collisional Frequency Shifts in 133Cs Fountain Clocks10.1103/PhysRevLett.86.3743article (journal)