More than one resource-ref in web.xml

I need to connect my application to another data source, hence, I've added another resource-ref in my web.xml. It looks like this:

<resource-ref>
    <description>A Schema DB Connection</description>
    <res-ref-name>jdbc/AschemaDS</res-ref-name>
    <res-type>javax.sql.DataSource</res-type>
    <res-auth>Container</res-auth>
    <res-sharing-scope>Shareable</res-sharing-scope>
</resource-ref>
<resource-ref>
    <description>B Schema DB Connection</description>
    <res-ref-name>jdbc/BschemaDS</res-ref-name>
    <res-type>javax.sql.DataSource</res-type>
    <res-auth>Container</res-auth>
    <res-sharing-scope>Shareable</res-sharing-scope>
</resource-ref>

Now, In eclipse, I can see an error regarding to DTD schema specification (web-app_2_3.dtd) around declaration like this:

The content of element type "web-app" must match "(icon?,display-name?,description?,distributable?,context-param*,filter*,filter-mapping*,listener*,servlet*,servlet-mapping*,session-config?,mime-mapping*,welcome-file-list?,error-page*,taglib*,resource-env-ref*,resource-ref*,security-constraint*,login-config?,security-role*,env-entry*,ejb-ref*,ejb-local-ref*)".

I though the asterisk (resource-ref*) meant "as many as you want"

Is there something missing in my configuration?