In theory, anyone seeking entry into Hong Kong receives 36 points for every year of marriage.

CNN: A TRAGEDY OR A FARCE?

As string theory involves intricate mathematics, the barrier to entry into its community is high.

ECONOMIST: Theoretical physics

Time tested economic theory tells us that in a free, unfettered market not constrained by onerous barriers to entry, the long term price of a commodity will approach its marginal cost of production.

FORBES: Gold Sets Up As The Next Great Short