html - Selecting from and including table rows that contain some text in xpath -

i'm new html agility pack , xpath. have table part of is:

                        ...                         <tbody class="tdata">                         <tr bgcolor="#ffffff">                         <td nowrap>crr004</td>                         <td nowrap>carrie</td>                         <td nowrap>021</td>                         <td nowrap>coal</td>                         <td nowrap>0.800</td>                         <td nowrap>55.000</td>                         <td nowrap>55.800</td>                         <td nowrap>fcr a</td>                         <td nowrap>&nbsp;</td>                         <td nowrap>&nbsp;</td>                         <td nowrap>&nbsp;</td>                         </tr></tbody>                          ...                          <tbody class="tdata">                         <tr bgcolor="#ffffff">                         <td nowrap>crr004</td>                         <td nowrap>carrie</td>                         <td nowrap>021</td>                         <td nowrap>coal</td>                         <td nowrap>0.800</td>                         <td nowrap>99.500</td>                         <td nowrap>100.300</td>                         <td nowrap>fcl b</td>                         <td nowrap>&nbsp;</td>                         <td nowrap>&nbsp;</td>                         <td nowrap>&nbsp;</td>                         </tr></tbody>                          <tbody class="tdata">                         <tr bgcolor="#ffffff">                         <td nowrap>crr004</td>                         <td nowrap>carrie</td>                         <td nowrap>034</td>                         <td nowrap>bone</td>                         <td nowrap>0.100</td>                         <td nowrap>100.300</td>                         <td nowrap>100.400</td>                         <td nowrap>fcl b</td>                         <td nowrap>&nbsp;</td>                         <td nowrap>&nbsp;</td>                         <td nowrap>&nbsp;</td>                         </tr></tbody>                          <tbody class="tdata">                         <tr bgcolor="#ffffff">                         <td nowrap>crr004</td>                         <td nowrap>carrie</td>                         <td nowrap>021</td>                         <td nowrap>coal</td>                         <td nowrap>0.400</td>                         <td nowrap>100.400</td>                         <td nowrap>100.800</td>                         <td nowrap>fcl b</td>                         <td nowrap>&nbsp;</td>                         <td nowrap>&nbsp;</td>                         <td nowrap>&nbsp;</td>                         </tr></tbody> 

using html agility pack, can grab entire table with:

doc.documentnode.selectnodes("//tbody[@class='tdata']/tr") 

but want select row 8th column contains "fcr a" last row containing "fcl b". row 2 row 14.

crr004  carrie  540 ss  1.100   53.900  55.000                crr004  carrie  021 coal    0.800   55.000  55.800  fcr             crr004  carrie  124 sh  4.200   55.800  60.000                crr004  carrie  320 s sh    1.400   60.000  61.400                crr004  carrie  540 ss  2.400   61.400  63.800                crr004  carrie  320 s sh    0.300   63.800  64.100                crr004  carrie  540 ss  15.900  64.100  80.000                crr004  carrie  749 ss w/coal str   10.000  80.000  90.000                crr004  carrie  540 ss  7.200   90.000  97.200                crr004  carrie  124 sh  0.500   97.200  97.700                crr004  carrie  114 black sh    1.800   97.700  99.500                crr004  carrie  021 coal    0.800   99.500  100.300 fcl b             crr004  carrie  034 bone    0.100   100.300 100.400 fcl b             crr004  carrie  021 coal    0.400   100.400 100.800 fcl b             crr004  carrie  120 cl sh   0.800   100.800 101.600       

i tried doc.documentnode.selectnodes("//tbody[@class='tdata']/tr[following-sibling::td[8]='fcr a' , preceding-sibling::td[8]='fcl b']")) among others no avail. appreciated. thanks.

after playing around splash's suggestion, works:

//tr[contains(.,'fcr a')]|//tr[following::tr[td[8][.= 'fcl b']][last()] , preceding::tr[td[8][.= 'fcr a']][last()]]|//tr[contains(.,'fcl b')] 

but shorter expression appreciated.