Measurements of X-ray source positions by the scanning modulation collimator on HEAO-1. Schwartz, D. A. ; Gursky, H. ; Bradt, H. ; Doxsey, R. E. ; Schwarz, J. ; Dower, R. G. ; Fabbiano, G. ; Griffiths, R. E. ; Johnston, M. ; Leach, R. ; Ramsey, A. ; Spada, G. Abstract Publication: Bulletin of the American Astronomical Society Pub Date: September 1977 Bibcode: 1977BAAS....9..626S