If you're having trouble finding relevant articles using your search terms, you may want to take a step back and think about the words that you’re using to search. Too many results may mean that your terms are too broad, while too few may mean that you’re searching too narrow of a topic. It often helps to think of related words or concepts to search.
You may find it useful to consider the following questions, keeping in mind that they can be applied both ways, to narrow or broaden a search:
Are my terms part of a whole? For example, HVAC systems is a narrower term for built environment. A simple Google search will often uncover these narrower parts of broad search terms, or vice-versa. Consider which you want to be searching.
Can the concept be focused geographically? By city, county, state, region, country, continent?
Can the concept be focused chronologically? Historically, specific dates, etc.?