From Longman Dictionary of Contemporary Englishconcerted effort/action/attack etcconcerted effort/action/attack etcTOGETHERa concerted effort etc is done by people working together in a carefully planned and very determined way Libraries have made a concerted effort to attract young people. → concerted
Examples from the Corpus
made ... concerted effort• She has also made a concerted effort to improve her knowledge.• Courtland County officials have made a concerted effort to raise the standards of education. 