Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
van can » van canh, van ban, ban can
can tac » canh tac, cac tac, cong tac
tue cua » te cua
nang o » nang co, nang ho, nang ro
de cua » le cua, te cua, dieu cua
o hoi » co hoi, o hoc, o hai
gia » giao

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 ky nang o hoi. hieu van can tac gia thanh ((de cua) or (tue cua)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang o hoi. hieu van can tac gia thanh ((de cua) OR (tue cua)) te.
• Adding a wildcard symbol may retrieve word variants: su sach ky nang o hoi. hieu van can tac gia thanh ((de cua) or (tue cua)) te*.