Jamma River
The Jamma River is a river in central Ethiopia and a tributary of the Abay ( or Blue Nile ) on its right side . 
<triplet> Jamma River <subj> Abay <obj> mouth of the watercourse <subj> Blue Nile <obj> mouth of the watercourse <triplet> Abay <subj> Jamma River <obj> tributary <triplet> Blue Nile <subj> Jamma River <obj> tributary <subj> Ethiopia <obj> basin country