If two sources contradict one another . conduct additional research
pick the information with the better reputation
use the information that supports your thesis/claim
use common sense

Which line in this excerpt from "the love song of j. alfred prufrock" by t.s. eliot uses synecdoche? shall i say, i have gone at dusk through narrow streets and watched the smoke that rises from the pipes of lonely men in shirt-sleeves, leaning out of windows? i should have been a pair of ragged claws scuttling across the floors of silent seas.