\begin{table}%t1 \caption{\label{tab1}Journal of observations.} %\centerline {\small \begin{tabular}{l c c c l} \hline\hline \multicolumn{1}{c}{Source} & \multicolumn{1}{c}{$z^a$} & \multicolumn{1}{c}{$E(B-V)^b$} & \multicolumn{1}{c}{${\rm Exp.}^c$} & \multicolumn{1}{c}{Date}\\ \hline\noalign{\smallskip} TN J0121$+$1320& 3.516& 0.039& 23~400& 2005 Oct. 28, Nov. 20,\\ & & & & 2006 Sep. 17, 20\\ TN J0205$+$2242& 3.506& 0.100& 5400& 2005 Oct. 1\\ MRC 0316$-$257& 3.130& 0.014& 10~800& 2006 Jul. 27, Aug. 25, Oct.~2\\ USS 0417$-$181& 2.773& 0.048& 2700& 2006 Oct. 2\\ TN J0920$-$0712& 2.760& 0.041& 10~800& 2006 Apr. 3, 4\\ WN J1123$+$3141& 3.217& 0.018& 14~400& 2005 Dec. 28,\\ & & & & 2006 Apr. 5, May 27, Jun. 20\\ 4C 24.28& 2.879& 0.018& 10~800& 2006 Apr. 23\\ USS 1545$-$234& 2.755& 0.257& 14~400& 2006 Apr. 5, 23, 24\\ USS 2202$+$128& 2.706& 0.067& 10~800& 2006 Jul. 2, Aug. 16\\ \hline \end{tabular}} \medskip $^a$~The redshift based on NED (NASA/IPAC Extragalactic Database); $^b$~galactic extinction [mag] given by Schlegel et~al. (\cite{Schlegel1998}); $^c$~total exposure time~[s]. \end{table}