Except “Modified” none of the fields are being displayed in XSL

I have a site in which there is a library named "Pages". This is the standard library where all pages that you create comes. 

Using XSL, I am trying to display page links on my home page. Problem is except "Modified" field, none of the fields are being displayed.  

So basically doing the following in my XSL works i.e. Modified date is displayed.  

    <xsl:value-of select="@Modified">

But other than that none of the fields are being displayed. So for e.g. if I do this:  

    <xsl:value-of select="@Title">
    <xsl:value-of select="@Name">
    <xsl:value-of select="@Contact">

They are not being displayed even though these fields exists.

Any reason why is that?  

Secondly I want to know how can I display URL of page? Something like following which will give me URL of the page in Pages library.

    <xsl:value-of select="@URL">