$z_{\rm abs}=4.155$ with [H]{}[i]{} column of log $N_{{\rm H}\,{\sc \rm I}}=19.23\pm0.12$ with a fixed $b=20$ km s$^{-1}$. The metal lines associated with this system are either blended with other features or not covered by our data so that this detection is based on the Lyman line only and is a little less secure than the others. The detection of absorption lines from the Lyman series confirm the presence of the sub-DLA. Fig. \[J1723+2243\] shows our best fit result of [H]{}[i]{} lines.

    \

15. LBQS 2114-4347 ($z_{\rm em}=2.040$). The quasar has been discovered as part of the Large Bright Quasar Survey (LBQS; @morris91). No absorber has been previously reported in this quasar [@peroux03]. We observed, for the first time, a sub-DLA at $z_{\rm abs}=1.912$ with best fit column density of log $N_{{\rm H}\,{\sc \rm I}}=19.50\pm0.10$ and $b=31.7\pm3.4$ km s$^{-1}$. Several metal absorption lines from [O]{}[i]{} $\lambda$ 1302, [Fe]{}[ii]{} $\lambda\lambda\lambda\lambda\lambda\lambda$ 1144, 1608, 2344, 2374, 2382, 2586, [Si]{}[ii]{} $\lambda\lambda\lambda\lambda\lambda$ 1193, 1260, 1304, 1526, 1808, [C]{}[ii]{} $\lambda$ 1334, [Al]{}[ii]{} $\lambda$ 1670, [Mg]{}[ii]{} $\lambda\lambda$ 2796, 2803, [Si]{}[iv]{} $\lambda\lambda$ 1393, 1402, and [C]{}[iv]{} $\lambda\lambda$ 1548, 1550 at the redshift of the sub-DLA are covered in the red part of the spectrum. Fig. \[2114-4347\] shows our best 