However, experts around the world are puzzling over this challenge constantly, and some solutions are emerging.

FORBES: Crimes No One Can Stop -- Attackers No One Can Find

This may seem puzzling to people with memories of two world wars (not to mention the Falklands).

ECONOMIST: Foreign policy

This seems to be the world Nancy Folbre has in mind in a puzzling piece lamenting the competition that skilled workers increasingly face.

FORBES: How Can You Protect An Entire Economy From Competition?

" appeared in the 1904 novel Jim Hickey by George Hobart, while "hep" was established enough by 1908 for the Saturday Evening Post puzzling as to whether you could "find anybody left in the world who isn't hep.

FORBES: Medialand