What is our nation's principal contribution to world art?

His principal contribution to scientific thought was the establishment of a mathematical basis for evolution.

His principal contributions were to the study of Oligochaeta.

It was completed in 1987, with the principal contribution from the Marcus Corporation.

However, his principal contribution was in the field of electronic music.

Wardell's principal contribution to his age lay in his church work.

Or is technology's principal contribution to be found in the hardware and software those companies buy and sell?

But his principal contribution is a long lawyer's brief in defense of the former Mayor's honesty.

The close correlation between words and music was Wolkenstein's principal artistic contribution.

This technique would subsequently become his principal contribution to sculpture.