" The Children of Llyr " followed in 1971 , " The Song of Rhiannon " in 1972 and " Prince of Annwn " in 1974 .
Head entity: the song of rhiannon Q7765241 11 12 13 14
Tail entity: the children of llyr Q16385272 1 2 3 4
Relation (head \u2192 tail): P155
Inverse relation (tail \u2192 head): P156