When developing your search strategy, it is helpful to brainstorm variations or synonyms of the key concepts you're researching. For example, if you are researching these stages of adulthood, you might try different combinations of the following search terms:
"social support "OR transitions
ageing OR adulthood
sexuality OR "sexual orientation" OR "gender identity"
When researching early/middle childhood, you might choose macro themes, such as: housing or "access to healthcare" ,or concepts associated with adulthood, like parenting, "working parents", divorce, marriage, spirituality or faith.
While Social Work Abstracts and Social Services Abstracts are always best bets for finding social work literature, consider searching the following databases as well.