( ( ( ( Specific ( authoritative sources ) ) ( such ( as ( ( the Registry ) ( of ( ( ( ( ( ( ( Toxic Effects ) ( of ( ( Chemical Substances ) ( -LRB- ( RTECS -RRB- ) ) ) ) ) , ) ( ( the ( National ( Toxicology ( Program ( -LRB- ( NTP ( -RRB- ( Annual Report ) ) ) ) ) ) ) ) ( on Carcinogens ) ) ) , ) and ) ( ( the ( International Agency ) ) ( for ( Research ( on Cancer ) ) ) ) ) ) ) ) ) ) ( -LRB- ( IARC -RRB- ) ) ) ( ( monographs ( serve ( as ( ( primary sources ) ( of ( toxic ( chemical information ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NP (JJ Specific) (JJ authoritative) (NNS sources)) (PP (JJ such) (IN as) (NP (NP (DT the) (NN Registry)) (PP (IN of) (NP (NP (NP (JJ Toxic) (NNPS Effects)) (PP (IN of) (NP (NP (NNP Chemical) (NNP Substances)) (PRN (-LRB- -LRB-) (NP (NNP RTECS)) (-RRB- -RRB-))))) (, ,) (NP (NP (DT the) (NNP National) (NNP Toxicology) (NNP Program) (-LRB- -LRB-) (NNP NTP) (-RRB- -RRB-) (NNP Annual) (NNP Report)) (PP (IN on) (NP (NNP Carcinogens)))) (, ,) (CC and) (NP (NP (DT the) (NNP International) (NNP Agency)) (PP (IN for) (NP (NP (NNP Research)) (PP (IN on) (NP (NNP Cancer))))))))))) (PRN (-LRB- -LRB-) (NP (NNP IARC)) (-RRB- -RRB-))) (VP (VBZ monographs) (VP (VB serve) (PP (IN as) (NP (NP (JJ primary) (NNS sources)) (PP (IN of) (NP (JJ toxic) (NN chemical) (NN information))))))) (. .)))
Specific authoritative sources such as the Registry of Toxic Effects of Chemical Substances (RTECS), the National Toxicology Program (NTP) Annual Report on Carcinogens, and the International Agency for Research on Cancer (IARC) monographs serve as primary sources of toxic chemical information.
(ROOT (S (NP (NNS Cigarettes)) (VP (VBP are) (NP (NP (DT a) (JJ major) (NN source)) (PP (IN of) (NP (NP (NNS carcinogens)) (, ,) (NP (NP (DT a) (NN kind)) (PP (IN of) (NP (NP (NN chemical) (NNS substances)) (VP (VBN linked) (PP (IN with) (NP (NN cancer))))))))))) (. .)))