Potassium fluoride doped LaOFeAs multi-band superconductor: Evidence of extremely high upper critical fieldJ. Prakash, S. J. Singh, S. L. Samal, S. Patnaik and A. K. GanguliEPL, 84 5 (2008) 57003DOI: https://doi.org/10.1209/0295-5075/84/57003