TY - JOUR AU - P. Engels AU - I. Coddington AU - P. Haljan AU - V. Schweikhard AU - Eric Cornell BT - Physical Review Letters DA - 2003-05 DO - 10.1103/PhysRevLett.90.170405 PY - 2003 T2 - Physical Review Letters TI - Observation of Long-Lived Vortex Aggregates in Rapidly Rotating Bose-Einstein Condensates VL - 90 SN - 0031-9007 ER -