Wait a minute," thought I, "there are knotty philosophical issues here.

To say that the regulators face some knotty issues is an understatement.

Among the knottier issues now before the Legislature is how to balance the budget, which has been battered by low oil prices and a recession.

Before the project can begin, an assortment of knotty issues must be resolved.

It's not completely clear just when this became such a knotty issue here.

But the two different approaches illustrate the knotty issues facing researchers and designers in many fields.

The program also raises knotty legal issues raised by the program that have not been tested in court.

In large measure he doesn't always win because he takes on some pretty knotty issues.

But many of the knottiest issues revolve around race.