There are a number of advanced searching techniques you can use to improve the thoroughness of your searches.
The symbols used for these advanced searching techniques may change depending on which database you are searching in so make sure to check the help button 
next to the database name for more information on which symbols to use in that database: https://libguides.tees.ac.uk/az.php?
The main advanced searching techniques used are: truncation, phrase searching and wildcards.
Truncation is also known as “stemming”. You can use it to search for a term and variant spellings of that term, by substituting the letters at the end of the word for an asterisk (*). Your search then finds every word that begins with the letters you have entered. For example, handwash* will retrieve handwash, handwashing.
You can use double speech marks ("") when you want to find an exact phrase, for example, "healthcare workers”. This will find only documents where those words appear next to each other and in the same order.
You can also use truncation and phrase searching together. This can be useful when you want to use phrase searching but still pick up the various endings, including plurals.
As only the exact phrase is searched for, a search for “Health care worker” would not find the plural health care workers. To overcome this issue, you could use truncation within your phrase, “health care worker*”.
Also a search for “hand wash*” would keep your two keywords together, in the same order, as well as finding hand washing.
There are 2 symbols which are generally used for the wildcard:
To use the # wildcard, enter your search terms and place # where an alternate spelling might contain an extra character. For example, type colo#r to find all records containing color or colour. Type p#ediatric to find all records with pediatric or paediatric.
To use the ? wildcard, enter your search terms and replace the unknown character with a ?. For example, type ne?t to find all records containing neat, nest or next.