\begin{table}%t2
\caption{Summary of single-dish millimetre line observations used in the analysis.}
\label{intensities_summary}
%\centerline
{
\begin{tabular}{lllcc}
\hline
\hline
\multicolumn{1}{l}{{Source}} &
\multicolumn{1}{c}{{Telescope}} &
\multicolumn{1}{c}{{Transition}} &
\multicolumn{1}{c}{$\int T_{{\rm mb}}{\rm d}v$}  &
\multicolumn{1}{c}{{Ref.}} 
\\
&
 &
 & 
\multicolumn{1}{c}{[K~km~s$^{-1}$]}\\
\hline
R Scl         & IRAM & CO(1--0) & 76.2 & 4\\
                   & IRAM & CO(2--1) &       67.7 & 4\\
                   & SEST & CO(1--0) &        26.1 & 4\\
                   & SEST & CO(2--1) &    47.8 & 4\\
                   & SEST & CO(3--2) &      63.7 & 3\\
                   & JCMT & CO(2--1) &      50.6 & 6\\
                   & JCMT & CO(3--2) &     62.8 & 1\\
                   & JCMT & CO(4--3) &    63.2 & 1\\
                   & SEST & $^{13}$CO(1--0) &  1.9 & 5\\
                   & SEST & $^{13}$CO(2--1) & 4.2 & 5\\
                   & SEST & HCN(1--0) & 1.3 & 3\\
                   & SEST & HCN(3--2) & 7.7 & 3\\
                   & SEST & HCN(4--3) & 3.9 & 3\\
                   & HHT & HCN(3--2) & 2.4 & 7\\
                   & HHT & HCN(4--3) & 4.1 & 7\\
U Cam     & IRAM & CO(1--0) &                             21.8 &  1  \\
                  & IRAM & CO(2--1) &                             97.9 &  1  \\ 
                  & JCMT & CO(3--2) &                             66.7 & 1  \\
                  & JCMT & CO(4--3) &                              54.6 & 1 \\
U Ant        & SEST & CO(1--0) &                      10.8 &  3  \\
                  & SEST & CO(2--1) &                      13.1 &  3  \\ 
                  & SEST & CO(3--2) &   9.7 & 3  \\
V644 Sco & SEST & CO(1--0) &   7.6  & 3\\ 
                   & SEST & CO(2--1) &    20.7  & 3\\ 
                   & SEST & CO(3--2) &      21.4  & 3\\ 
                   & JCMT & CO(2--1) &       22.2  & 6\\ 
                   & JCMT & $^{13}$CO(2--1) & 1.1 &1\\
                   & SEST & HCN(1--0) & 0.3 & 1 \\ 
                   & SEST  & HCN(3--2) & 0.4 & 1 \\
DR Ser    & SEST & CO(1--0) & 3.7 & 2 \\
                  & NRAO & CO(2--1) &   11.3 & 2 \\
                  & JCMT & CO(3--2) &     14.7 & 1 \\
                  & JCMT  & CO(4--3) &  8.5 & 1 \\
                  & OSO & HCN(1--0) & 0.6 & 1\\
S Sct         & SEST & CO(1--0) & 5.8 &  3  \\
                  & SEST & CO(2--1) &  4.3 &  3  \\ 
                  & SEST & CO(3--2) & 3.1 & 3  \\
                  & SEST & $^{13}$CO(1--0) &  0.2 & 3 \\
TT Cyg     & SEST & CO(1--0) &  5.0 &  1  \\
                   & OSO & CO(1--0) &  6.4 &  3  \\
                  & IRAM & CO(1--0) &  7.5 &  3  \\ 
                  & IRAM & CO(2--1) &  6.0 &  3  \\ 
\hline
\end{tabular}}
\medskip
Refs. --  1) This paper; 2) \citet{Schoeier01}; 3) \citet{Olofsson96}; 4) \citet{Olofsson93a}; 5) \citet{Schoeier00}; 6)~JCMT public archive; 7) \citet{Bieging01}.
\end{table}