(S (S (PP (VBG According) (PP (TO to) (BASENP (NNP Reuters)))) (COMMA ,) (S (S (BASENP (JJ Georgian) (NNS troops)) (VP (VP (VBD did) (RB not)) (VP (VB observe) (BASENP (DT the) (NN cease) (NN fire))))) (COMMA ,) (SBAR (IN since) (S (BASENP (NN six) (NNS helicopters)) (VP (VP (VBD bombed) (BASENP (NNP Tskhinvali))) (PP (IN on) (BASENP (NNP August) (NN 11)))))))) (PERIOD .))