X-Ray Pulse Timing Measurements of X-Perseus Weisskopf, M. C. ; Darbro, W. ; Elsner, R. ; Naranan, S. ; Williams, A. ; Grindlay, J. E. ; Sutherland, P. G. ; White, N. Abstract Publication: Bulletin of the American Astronomical Society Pub Date: September 1982 Bibcode: 1982BAAS...14Q.965W