This has not been studied systematically, although there are reports of its success.

The topic was not systematically studied, however, for almost another century.

The subject was first studied systematically by Ramanujan starting in 1915.

It is considered rare, with few known localities, but its range has not yet been systematically studied.

Customer service in the accounting field is seldom studied systematically.

The only complex polytopes to have been systematically studied are the regular ones.

Wilhelm Röntgen was the first to systematically study them, in 1895.

This aspect has been systematically studied by a number of workers including our group and allows some firm conclusions to be drawn.

However, its actual effectiveness has never been systematically studied.

The functions of the cingulate motor areas have not yet been systematically studied.