function cbnet_parameter_queryvars( $qvars ) {
    $qvars[] = 'utm_source';
    return $qvars;
}
add_filter( 'query_vars', 'cbnet_parameter_queryvars' );

global $wp_query;
$no_pagination = false;

if(isset( $wp_query->query_vars['utm_source'])) {
    $no_pagination = $wp_query->query_vars['utm_source'];
}

if( $no_pagination ) {
    the_content();
    wp_link_pages(array('next_or_number'=>'next', 'before'=>'<div id="link-pages"><center>', 'after'=>'</center></div>', 'previouspagelink' => ' < PREVIOUS ', 'nextpagelink'=>' NEXT >'));
} else {
    echo apply_filters( 'the_content', $post->post_content );
    $page=$numpages+1;
}