Validation site web [validator.w3]

Bonjour,
j'ai essayer de valider mon site via validator.w3 mais mon problème c que j'ai pas réussi a comprendre certain erreurs, qui peut m'aider a les résoudre.
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Error Line 306, Column 148: general entity "select" not defined and no default entity

...;>  <a href="index.html?res&select=jeux" style="color:...


This is usually a cascading error caused by a an undefined entity reference or use of an unencoded ampersand (&) in an URL or body text. See the previous message for further details.
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Error Line 306, Column 154: reference to entity "select" for which no system identifier could be generated

...p; <a href="index.html?res&select=jeux" style="color:#09F;T...


This is usually a cascading error caused by a an undefined entity reference or use of an unencoded ampersand (&) in an URL or body text. See the previous message for further details.
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merci