 Finkelstein noted 20 instances , in as many pages , where Dershowitz 's book cites the same sources and passages used by Joan Peters in her book , in largely the same sequence , with <unk> in the same places . In two instances , Dershowitz <unk> Peters 's errors ( see below ) . From this Finkelstein concluded that Dershowitz had not checked the original sources himself , contrary to the latter 's claims . Finkelstein suggests that this copying of quotations amounts to copying ideas . Examining a copy of a proof of Dershowitz 's book he managed to obtain , he found evidence that Dershowitz had his <unk> assistant , Holly Beth Billington , check in the Harvard library the sources he had read in Peters 's book . Dershowitz answered the charge in a letter to the University of California 's Press Director <unk> <unk> , arguing that Finkelstein had made up the smoking gun quotation , in that he had changed its wording ( from ' cite ' to ' copy ' ) in his book . In public debate he has stated that if " somebody borrowed the quote without going to check back on whether Mark Twain had said that , obviously that would be a serious charge " ; however , he insisted emphatically that he himself did not do that , that he had indeed checked the original source by Twain . 
