\begin{table}%t6
\caption{Ionised boundary layer pressures, internal pressures and densities of clouds observed in molecular line wavelengths. A dash indicates non-detection in the NVSS.
\label{tbl:Pint}}
\centerline {\begin{tabular}{ccccc}\hline\hline
SFO Object & IBL pressure & &Internal Pressure & Internal Molecular Density \\
 & (10$^{5}$ cm$^{-3}$ K) & & (10$^{5}$ cm$^{-3}$ K) &  $(10^3 ~\rm cm^{-3})$\\ \hline
4$^{a}$	 & 61.8  &    & 8.2   & 50.0   \\
5$^{b}$	 & 35.8  &    & 32.3  & 11.0  \\	    
11$^{c}$ & 82.0  &    & 25.0  & 2.5    \\
13$^{d}$ & 20.0  &    & 16.3  & 2.0    \\
16$^{d}$ &  --	 &    & 0.3   & 2.0    \\
18$^{d}$ &  --	 &    & 7.8   & 16.6   \\
20$^{e}$ &  --	 &    & 6.9   & 20.0   \\
25$^{d}$ & 20.8  &    & 12.5  & 7.4    \\
37$^{f}$ & 35.1  &    & 1.5   & 3.0    \\\hline	    
\end{tabular}}
\par
\smallskip
$^{a}$\citet{Jansen94}; $^{b}$\citet{Lefloch97}; $^{c}$\citet{searching}; $^{d}$\citet{Devries}; $^{e}$\citet{Cernicharo1992}; $^{f}$\citet{Duvert1990}	
\end{table}