The simplest way to retrieve that information is to just write the words you wish to find one after the other. If you write more than one, only those records will be retrieved in which all the words are found. Don't worry about upper- or lowercase typing, nor accents. E.g., child labour finds records with the words child and labour anywhere; both must be present, but not necessarily as the term child labour. (If you have performed searches like this in other databases, you may have had to type child AND labour; CISDOC understands AND as well.)
For truncation of words use the * sign. E.g., child* will retrieve records containing child, children, childhood, etc. Actually you can use it on either or both sides, e.g.:*child* would return Fairchild as author as well.
If you are looking for a multi-word term or phrase, use quotes. E.g., "child labour" retrieves records where this phrase appears in the record, but not those where child and labour appear in different order or not next to each other. You can combine search items in the same query: "child labour" shipbreaking retrieves records where both the phrase "child labour" and the word shipbreaking appear.