Perhaps you should try some spelling variations:
hang tai » hang va, dung tai
hanh tai » thanh tai, han tai, hinh tai
xang dau » hang dau
cam luc » cam xuc, cau luc
luc van » luoc van, luu van, duc van
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach kem
hieu ve » hieu va, hieu van
dau hoi » cau hoi, dai hoi, dan hoi
sach ty » sach y, sach tu, sach thu
ve cam » ve cham, ve cac, va cam

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)) xang dau hoi. hieu ve cam luc van ((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)) xang dau hoi. hieu ve cam luc van ((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)) xang dau hoi. hieu ve cam luc van ((hanh tai) OR (hang tai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) or (sach ty)) xang dau hoi. hieu ve cam luc van ((hanh tai) OR (hang tai)) cua tre*.