If you're not happy with your results, or you're getting too many or not enough results, then you will need to refine your search.
When you evaluated your results, you should have asked this question:
"If a result is relevant, are there words and phrases in it that you could use to rephrase your search?" These could be words in the title or in the summary. Here's a result for a search on 'electrical safety standards' :
You see the title, the authors, where the article was published and beneath that, 'Subjects'. These are keywords supplied by the library resource provider that describe the content of the article. Perhaps some of these keywords could be used in other searches (e.g. 'electricity safety, 'hazards', 'electricians')
Click on the title. This is what you will see
In addition to to the subject keywords that are supplied by the library resource provider, there are are also author supplied keywords - perhaps these could be used in other searches (for example 'electrical hazard classification' 'electrical injury', 'electrical safety'). Som results wil have summaries. There may be words and phrases in the summary that might be useful in a search.
Who wrote the article? If the authors wrote this article, which is relevant, maybe they have written other relevant articles - perhaps you could try searching for the authors?
Where was the article published? Perhaps the source might have published other articles that are relevant to your topic?