Perhaps you should try some spelling variations:
thien van » thi van
hac nuoc » hoc nuoc, cac nuoc, phap nuoc
nang tri » lang tri, nang thi, quang tri
nang tai » hang tai, tang tai, sang tai
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
van hac » van hoc, van ha, van hai
cua tre » cua te, cuu tre, cua triet
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: tu sach ky nang x hoi. thien van hac nuoc va ((nang tri) or (nang tai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x hoi. thien van hac nuoc va ((nang tri) OR (nang tai)) cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x hoi. thien van hac nuoc va ((nang tri) or (nang tai)) cua tre*.