Submilliarcsecond shift of the brightness peak of the radio sources 1928+738 and 2007+777

1. Guirado, J.C.
2. Marcaide, J.M.
3. Ros, E.
4. Ratner, M.I.
5. Shapiro, I.I.
6. Quirrenbach, A.
7. Witzel, A.