A Search for Point Sources of Cosmic Primary Rays Which Produce Single   Muon Tracks at Ground Level
  An increased data sample of identified secondary muons is collected at detection level. Project GRAND identifies secondary cosmic ray muons from electrons utilizing a thin steel absorber and tracking (PWC) chambers. The resulting angular resolution for the primary is about +/- 5 degrees. Since there is a 1.5% probability that a 100 GeV gamma primary will produce a single muon track at ground level, the high statistics allows a search for angular enhancements due to gammas. More than 100 billion muons are identified and analyzed. A table of stellar sources is examined. 
A. Roesch, J. Carpenter, S. Desch, J. Gress, T.F. Lin, and J. Poirier