Greenberg is the man who spent nearly four decades building AIG into a global insurance power.

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It took years of focused effort among many nations to bring the NPT into force four decades ago and to sustain it as the most widely embraced nuclear agreement in history.

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During the four decades from the 1960s, women have been marching into America's labour force in ever greater numbers.

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Encouraged into the field by Elizabeth David, four decades of his scholarship and erudition were recognized last year when he was awarded the Erasmus Prize.

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After doing their work, the rockets plummeted into the ocean, where they have been undiscovered for four decades.

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If this plan fails to provide a satisfactory return over four decades between entering the work force and retiring, it will be because the U.S. economy goes into a long-term funk.

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