Perhaps you should try some spelling variations:
hanh lai » hanh lam, hanh tai, thanh lap
sang mai » sang ma, sang tai, lang mai
cua tre » cua te, cuu tre, cua triet
va hanh » van hanh, va thanh, va danh
cac duc » cac du, cao duc, cac dac
hieu va » lieu va, hieu qua
sach ky » sach y, sach ty, sach kem
mai hoi » mai khoi, dai hoi, lai hoi
cu tren » tu tren, dua tren
sac ky » cac ky, sai ky

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 (sac ky)) sang mai hoi. hieu va cac duc va hanh lai ((cua tre) or (cu tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ky) OR (sac ky)) sang mai hoi. hieu va cac duc va hanh lai ((cua tre) OR (cu tren)).
• Adding a wildcard symbol may retrieve word variants: te ((sach ky) or (sac ky)) sang mai hoi. hieu va cac duc va hanh lai ((cua tre) or (cu tren))*.