Perhaps you should try some spelling variations:
patients safety » patient safety
de litterature » la litterature, et litterature
agents safety » plants safety, accidents safety
des filosofia » de filosofia, e filosofia, di filosofia
filosofia de » filosofia del
studie des » studie der, studium des, studie die

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "((agents safety) OR (patients safety)) studie des filosofia de litterature*".