His principal artistic work was the design of books and bindings.

This led to his principal work on three long-term field projects.

My principal metamathematical work has been called destructive, and not without reason.

The monument still stands and is the principal public work of art in the borough.

The cathedral was constructed from the 13th to 15th centuries, with the principal work done in the 14th century.

Concerts - about 100 a year - have long been their principal work.

This is considered his principal work and a classic of public international law.

Its principal work is the care of orphaned street children.

They have schools, and the principal work seems to be among the children.

His principal work for the stage, however, was as a librettist.