[XeTeX] Concrete fonts

[José Carlos Santos]

On 08-06-2011 15:32, Diederick C. Niehorster wrote:

> The default font used by fontspec is latin modern, which is what you
> get. To change to another font, read the manual of fontspec (google it
> or use texdoc fontspec on the command line) which will show how to use
> it.

It says that I should use the command \setmainfont. But how do I 
discover which name should I use to get the Concrete fonts? I tried 
"Concrete", but I got an error message.

Best regards,

José Carlos Santos