Library books are still the principal commodity, accounting for a quarter of all books read.

The principal commodity was oysters, at that time plentiful in the area and much in demand.

Cotton is a principal commodity in the area.

The railroad's principal commodities are wood products and fertilizer.

In the 1890s the railroad's principal commodities were lumber, shingles, and potatoes.

Rice, the staple food, continued to be the principal commodity in this sector.

Most learning in retirement programs operate like co-ops, with members both creating and consuming the principal commodity, which is knowledge.

The railroad became prosperous, and the principal commodity it carried was milk.

Discussion question: What are the principal commodities exported by your country?

Our principal commodity, oil, is priced internationally in US dollars.