two direction difference

backward difference operator

central difference operator

Difference Operator

finite difference operator

Fitting method difference operator

inverse difference operator

Optimum Difference Operator

difference in difference

difference in difference (DD) method

Difference-in-difference

16-direction

2-D direction of arrival

2-D direction of arrival estimation

2-dimensional direction of arrival

2wire double direction

3rd direction

A Borel direction of largest type

a law of run in opposite direction

a law of run in the opposite direction