\begin{table}%t8
\caption{\label{linw}Velocities of C$^{18}$O and HCO$^+$ lines and asymmetry parameters.} 
\small%\centerline
{
\begin{tabular}{lcccc}
\hline\hline\noalign{\smallskip}
  Source & $v$ [km~s$^{-1}$]    &  $v$ [km~s$^{-1}$] & $\delta v$  & $R/B$  \\
  & N$_2$H$^+$  & HCO$^+$  \\
\hline 
L 1448 IRS 2 &  4.12                 & 4.53  & 0.82$^*$ & 1.28\\
L 1448 IRS 3 &  4.62         & 5.40  & 0.84 & -- \\
L 1448 C &    4.95       & 5.45  & 0.66 & 2.21 \\
L 1455 A1 &  5.10        & 5.12  & 0.03 & -- \\
L 1455 A2 &  4.88        & 4.94  & 0.17 & -- \\
Per 4 S &   7.52         & 7.25  & --0.92  & --   \\
Per 4 N &   7.57         & 7.44  & --0.40 & --   \\
Per 5 &   8.15          & 7.65  & --1.31  & --   \\
Per 6 &   5.94           & 6.02  & 0.05 &1.82  \\
IRAS 03282 &  6.06      & 6.62  & --0.91 & 0.57\\
Barnard 1-B & 6.62      & 6.01  & --0.74 & 0.45\\
HH 211 &    9.12         & 9.27  & 0.37$^*$  & 1.47  \\
Barnard 5 IRS 1 & 10.27   & 10.29 & 0.05 & 3.88\\
L 1527 &   5.90            & 5.38  & --1.60 & -- \\
L 483 &   5.40           & 5.87  & 1.06  & 3.18\\
SMM 5 &   8.12           & 8.18  & --0.33   & --       \\
L 723 &    11.11          & 11.43 & 0.46   & 1.61      \\
L 673 A &  6.87             & 6.97  & 0.19  & --    \\
B 335 &    8.34         & 7.90  & --1.10$^*$    & 0.833       \\
L 1157 &   2.67         & 3.16  & 0.75  & 1.54      \\
\hline
\end{tabular}}
\smallskip
Values for $\delta v$ marked with $^*$ are ambiguous due to nearly equal peak intensities of the double-peaked HCO$^+$ line, i.e. the $R/B$ ratio is close to one.
\end{table}