[Groff] help with refer

[Heinz-Jürgen Oertel]

Hello,
if someone has a small example document using the ms macros and refer, I'm 
sure it will help me understand the usage.

Im currently fighting with refer.
The data base is printeted at te buttom of the document, so fa so good.
I have put .R1/.R2 at the ducument end.
But whenever I try cite a document  

.[
CAN
.]

It gives not the result I expect and stderr says
 
refer:./proceeding_canfd.nroff:111: no matches for `CAN'

A small example document, please.

 Regards
   Heinz