Source Positions from Very Long Baseline Interferometer Observations. Clark, T. A. ; Counselman, D. C., III ; Hinteregger, H. F. ; Knight, C. A. ; Robertson, D. S. ; Rogers, A. E. E. ; Shapiro, I. I. ; Whitney, A. R. Abstract Publication: Bulletin of the American Astronomical Society Pub Date: January 1973 Bibcode: 1973BAAS....5...30C