Pick the important keywords or phrases to describe your topic.

Motor vehicles are major sources of gas-phase organic carbon, which includes volatile organic compounds. These emissions react in the atmosphere, leading to the formation of ozone.

Consider alternate terms.

Example:

motor vehicles or automobiles

high blood pressure or hypertension

Some databases search only the words you enter so you may miss other relevant papers. Many will allow you to enter a wild card character to search variations on the term.

Example:

robot* = robot, robots, robotics

Many databases will locate the keywords you enter anywhere in the citation. Consider focusing your results by entering an exact phrase using quotation marks.

“blood pressure”

“wearable device”