Edit Sharepoint dispForm.aspx Form to Display a of documents??

Hi All,

I need some guidance on editing the disForm.aspx form.  I create a "Customer" list and a "Document" library in Sharepoint. Both of them have a column called "Country".  When I open a customer list item, I would like the dispForm.aspx to also return a list of documents with matching Country.   Any suggestions on how best achieve this with minimal effort?  

Thanks in advance.