\begin{table}%t3
\caption{Journal and modes of VLBI observations.}\label{t_journal}
%\centering
\par
\begin{tabular}{c|c|c|l}
\hline \hline
\multicolumn{1}{c|}{Source} &
\multicolumn{3}{c}{Networks, frequencies and recording systems} \\
\cline{2-4}
& VLBA, 1.7~GHz &
\multicolumn{2}{l}{EVN, 5~GHz / recording} \\
\hline
0747+314 & 19 Sep. 1998 & 16 Feb. 1998 & Mk~IIIB\\
0811+360 & '' & ''\\
0902+416 & '' & ''\\
1123+340 & '' & ''\\
1232+295 & '' & ''\\
1242+364 & '' & ''\\
1251+308 & '' & ''\\
\hline
1619+378 & 30 Mar. 2001 & 11 Feb. 2001 & Mk~IV\\
1632+391 & '' & ''\\
1656+391 & '' & ''\\
1709+303 & '' & ''\\
1717+315 & '' & ''\\
\hline
0853+291 & 06 May 2001 & 11 Feb. 2001 & Mk~IV\\
1343+386 & '' & ''\\
1441+409 & '' & ''\\
\hline
1123+340 & -- & 8 Jun. 2001 & Mk~IV\\
\hline
\end{tabular}
\end{table}