Arnaldo Bristol
He competed in the 110 metres hurdles at the 1964 , 1968 , 1972 and the 1976 Summer Olympics . 
<triplet> 1964 <subj> 1964 <obj> point in time <triplet> 1972 <subj> 1976 Summer Olympics <obj> followed by <triplet> 1976 Summer Olympics <subj> 1972 <obj> follows