(S (S (BASENP (DT This) (NN research)) (VP (VBD was) (ADJP (ADJP (JJ useful) (PP (TO to) (BASENP (NNP Bethe)))) (PP (IN in) (S (VP (ADVP (RBR more) (RB quantitatively)) (VP (VBG developing) (NP (NP (BASENP (NNP Niels) (NNP Bohr) (POS 's)) (NN theory)) (PP (IN of) (BASENP (DT the) (NN compound) (NN nucleus))))))))))) (PERIOD .))