Information searches are an on-going process. It is not easy to find the right terms at once.
You can continue the search by taking into consideration the retrieved search results. Refine the search terms according to the subject terms in the references found. After trying several search terms, fields and connectors, you will find out how many results each of them or their combination retrieved. Browse the retrieved references to evaluate the relevance of the found documents. If the result is not satisfactory, refine the search phrase to retrieve a suitable amount of relevant references.
The result of the information search may sometimes be a surprise. The references found may not be relevant to the subject or you do not get any results. Sometimes the amount of references is so vast that it would take days to browse through them. In these cases, you may have to start the process from the beginning. Try specifying the concepts or conducting searches from different sources than the first time.
Rethink the search terms. The terms you used may be too broad (education -> musical education), and a search with a narrower term will produce a better search result. If there were too few or no results, use a broader term.