Our third method relies on the sectoral composition of employment in each state.

WHITEHOUSE: Recovery Act Third Quarterly Report - Supplement | The White House

Buchholz, a physicist and a nuclear engineer, is an expert at something called accelerator mass spectrometry, an extraordinarily precise method of determining the chemical composition of materials.

FORBES: Magazine Article

But, because of the simple modular method by which they are constructed, their composition can be changed easily.

ECONOMIST: Nanotechnology in biology