Perhaps you should try some spelling variations:
hang tai » hang va, dung tai
hanh tai » thanh tai, han tai, hinh tai
nang dau » hang dau, xang dau, nang du
cao luc » bao luc, cao duc, cao suc
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach kem
dau hoi » cau hoi, dai hoi, dan hoi
sach ty » sach y, sach tu, sach thu
luc va » duc va, tuc va, loc va
va cao » va cac, va co, va dao

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) or (sach ty)) nang dau hoi. lieu va cao luc va ((hanh tai) OR (hang tai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sach ty)) nang dau hoi. lieu va cao luc va ((hanh tai) OR (hang tai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) or (sach ty)) nang dau hoi. lieu va cao luc va ((hanh tai) OR (hang tai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) or (sach ty)) nang dau hoi. lieu va cao luc va ((hanh tai) OR (hang tai)) cua tre*.