It is not for use on its own. Whereas if the attitudinal option is chosen, the results will only show studies which contain people's attitudes to smoking. It is therefore most often used to locate historical records. The default is set at 100. Just a question of personal choice about how many search results you want it to show on the first screen.
All results are available, no matter what the entry here.
AND is the automatic, default option. All rights reserved. Last modified 14th October 1999.