TY - JOUR AU - B. Anderson AU - P. Haljan AU - Carl Wieman AU - Eric Cornell BT - Physical Review Letters DA - 2000-10 DO - 10.1103/PhysRevLett.85.2857 PY - 2000 SP - 2857 EP - 2860 T2 - Physical Review Letters TI - Vortex Precession in Bose-Einstein Condensates: Observations with Filled and Empty Cores VL - 85 SN - 0031-9007 ER -