Perhaps you should try some spelling variations:
thien van » thi van
hieu van » hieu va, lieu va, hieu ve
hanh dao » lanh dao, thanh dat, thanh dam
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
dao cua » dai cua, day cua, dan cua
cua tre » cua te, cuu tre, cua triet
luc va » tuc va, loc va
x hoi » xa hoi, o hoi, x ho

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 x hoi. ((hieu van) OR (thien van)) chat ((luc va) or (duc va)) hanh dao cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang x hoi. ((hieu van) OR (thien van)) chat ((luc va) OR (duc va)) hanh dao cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang x hoi. ((hieu van) OR (thien van)) chat ((luc va) or (duc va)) hanh dao cua tre*".