Perhaps you should try some spelling variations:
hanh tai » thanh tai, hang tai, han tai
van hanh » van thanh, ban hanh, van anh
cuc tre » cua tre, cuu tre, cuc thue
dac van » cac van, dao van, dam van
cac dac » cac dan, cac dai, cac bac
hieu ve » hieu va, hieu van
duc tre » duoc tren, duc tien
sach ky » sac ky, sach ty, sach kem
ve cac » va cac, vien cac
nang o » nang co, nang ho, nang ro
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 dac van hanh tai ((cuc tre) OR (duc 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 dac van hanh tai ((cuc tre) OR (duc 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 dac van hanh tai ((cuc tre) OR (duc tre))*".