( ( Graph ( ( showing ( ( the distribution ) ( of references ) ) ) ( by type ) ) ) . )
(ROOT (S (VP (VB Graph) (S (VP (VBG showing) (NP (NP (DT the) (NN distribution)) (PP (IN of) (NP (NNS references)))) (PP (IN by) (NP (NN type)))))) (. .)))
Graph showing the distribution of references by type.
(ROOT (S (NP (NNP Circle) (NNS graphs)) (VP (VBP are) (ADJP (JJ useful) (PP (IN for) (S (VP (VBG showing) (NP (NP (NNS percents)) (PP (IN of) (NP (DT a) (NN whole))))))))) (. .)))