Try using one of the following techniques to maximize your search.
Boolean: AND / OR / NOT
AND allows you to expand your search to include more terms, or to split up your terms in case there are times where other kanji could appear in-between terms
夫婦 AND 同姓 instead of 夫婦同姓
OR allows you to search for alternate terms / synonyms
新語 OR 流行語
NOT could be used when you do not want to include a particular term
allows you to search for terms that could have more than one ending.
Japan* / Japan? = Japan OR Japan's OR Japanese
allows you to substitute 0 or more letters in a word.
ukiyo*e / ukiyo?e = ukiyoe OR ukiyo-e
in many databases allows you to search for words together as a phrase
A full guide on truncation and wildcard use within library databases is available here.