VLBI observations of 21 extragalactic radio sources

We present the results of VLBI observations of 21 extragalactic radio sources carried out with an ad-hoc VLBI array including Shanghai, Urumqi, Noto, and Hartebeesthoek radio telescopes. Eleven sources are imaged, three of them for the first time with VLBI. Correlated flux densities of the remaining ten sources are given. From comparison with data taken at earlier epochs, the apparent superluminal motion is confirmed in four sources (0420-014, 0552+398, 1334-127 and 2345-167) and two more superluminal candidates (1504-166 and 2243-123) are found. The physical parameters of the four superluminal sources are derived