Perhaps you should try some spelling variations:
hanh doi » thanh doi, hanh noi, hang doi
su sach » vu sach
so sach » so sanh, bo sach, co sach
cao hoi » cau hoi, co hoi, cao hoc
hieu ve » hieu va, hieu van
xuc van » duc van, luc van, xuc ban
vuc van » duc van, luc van, thuc van
su viet » so viet
ve cam » ve cham, ve cac, va cam
doi su » oi su, don su, voi su

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) or (so sach)) ky nang cao hoi. hieu ve cam ((xuc van) OR (vuc van)) hanh doi su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) ky nang cao hoi. hieu ve cam ((xuc van) OR (vuc van)) hanh doi su viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (so sach)) ky nang cao hoi. hieu ve cam ((xuc van) OR (vuc van)) hanh doi su viet*".