A comfortable employee, the theory maintains, can produce more than a counterpart who struggles through the day.

Another theory maintains that they are of Veddoid origin.

Another theory, widely discredited, maintains that it was brought to England from Spain in the 14th century.

Critical theory maintains that ideology is the principal obstacle to human liberation.

Traditional international economic theory maintains that reducing barriers to labor mobility results in the equalization of wages across countries.

Alternative theories maintain that the halo formed all at once, and that material inside it later settled into a disk.

Classic economic theory maintains that people are rational and averse to risk.

This theory maintains that the relationship between Community law and national law is substantially a federal type of relationship.

Again, constitutional theory maintains that ministers are both collectively and individually responsible to Parliament for their actions.

A third theory maintains that the war acquired its popular name because it took place during the potato harvest.