Error parsing XML document

/mnt/stor/prosjekt/menota/public_html/meldingar/2008-05-16.page:12: parser error : Entity 'aring' not defined
            <title>R&aring;d for Menota</title>
                           ^
/mnt/stor/prosjekt/menota/public_html/meldingar/2008-05-16.page:40: parser error : Entity 'aring' not defined
         <head>Menotas h&aring;ndbok publisert i v. 2.0</head>
                               ^
/mnt/stor/prosjekt/menota/public_html/meldingar/2008-05-16.page:41: parser error : Entity 'aring' not defined
         <p>Menotas kodingsh&aring;ndbok, <title>The Menota Handbook</title>, fo
                                   ^
/mnt/stor/prosjekt/menota/public_html/meldingar/2008-05-16.page:44: parser error : Entity 'aelig' not defined
<p>HÄndboken har v&aelig;rt redigert av Odd Einar Haugen, med bidrag fra s&aeli
                          ^
/mnt/stor/prosjekt/menota/public_html/meldingar/2008-05-16.page:44: parser error : Entity 'aelig' not defined
>HÄndboken har v&aelig;rt redigert av Odd Einar Haugen, med bidrag fra s&aelig;
                                                                               ^
/mnt/stor/prosjekt/menota/public_html/meldingar/2008-05-16.page:50: parser error : Entity 'nbsp' not defined
<p>&nbsp;</p>
         ^
 at /usr/lib/perl5/site_perl/Aksis/XSLTransformer/Application.pm line 154