A new genetically engineered hormone could serve as a useful supplement to insulin.
Moreover it was a useful supplement to the circus income at leaner times.
Editors should find Menuspell, despite some inconsistencies, a useful supplement to their shelf of reference books.
Besides the forms, the cross-reference tables another useful supplement.
"Police have other serious matters to attend to, so this serves as a useful supplement to the overall enforcement effort."
The book could, however, act as a useful supplement for theatergoers, offering keys to understanding the code-breaking.
White's answers, in a useful supplement to the vast Hiss literature, are plausible but beyond proof.
In tropical tanks vegetarian fish, like the larger barbs will also find it a useful supplement to their diet.
Although the Internet can often be a useful and expedient supplement, it does not supplant traditional library research methods.
"It is thus a necessary and useful supplement to the public sector."