It is a complicated problem with which Obama will have to wrestle.

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"It is without a doubt the most complicated problem I've ever had to solve, " says Kensey, who also invented a device to stop arterial bleeding during surgical procedures.

FORBES: The Plot Thickens

The development of the Tethyan Realm is such a complicated problem that it remains far from being clarified.

UNESCO: EARTH SCIENCES FOR SOCIETY

From my perspective, this is a simple problem that has very complicated politics and emotion that make it difficult to make progress.

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The problem for traders is that it is much more complicated to create models for a world of fat tails than for a world of bell curves.

ECONOMIST: Buttonwood

If the child is a U.S. citizen, even if the mother may not be, it's a very complicated problem.

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