Perhaps you should try some spelling variations:
hang tai » hang va, dung tai
hanh tai » thanh tai, han tai, hinh tai
sach ky » sac ky, sach ty, sach kem
duc van » duc va, duc tan, duc manh
cac duc » cac du, cao duc, cac dac
cuc tre » duc tre, cua tre, cuu tre
hieu ve » hieu va, hieu van
nang o » nang co, nang ho, nang ro
ve cac » va cac, vien cac
o hai » co hai, so hai, o lai

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sach ky) or (sach y)) nang o hai. hieu ve cac duc van ((hanh tai) OR (hang tai)) cuc tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ky) OR (sach y)) nang o hai. hieu ve cac duc van ((hanh tai) OR (hang tai)) cuc tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach ky) or (sach y)) nang o hai. hieu ve cac duc van ((hanh tai) OR (hang tai)) cuc tre*".