Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
su triet » su viet, su tien, ve triet
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
cau hoc » cau hoi, cau hoa, cao hoc
hoc van » hoc dan, hoc va, hoc vat
hanh va » hang va, hanh vi
y lang » o lang, tay lang, yen lang
_ lang » o lang, _ land

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ((y lang) OR (_ lang)) xa hoi. ((hieu ve) or (lieu va)) cau hoc van hanh va su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((y lang) OR (_ lang)) xa hoi. ((hieu ve) OR (lieu va)) cau hoc van hanh va su triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((y lang) OR (_ lang)) xa hoi. ((hieu ve) or (lieu va)) cau hoc van hanh va su triet*".