Optical Identification of Transient X-Ray Sources Positioned with the HEAO-1 Modulation Collimator Griffiths, R. E. ; Bradt, H. ; Briel, U. ; Dower, R. ; Doxsey, R. ; Fabbiano, G. ; Gursky, H. ; Johnston, M. ; Leach, R. ; Murdin, P. ; Ramsey, A. ; Schwartz, D. ; Schwarz, J. Abstract Publication: X-ray Astronomy Pub Date: 1979 Bibcode: 1979xras.proc...93G