Perhaps you should try some spelling variations:
sang mai » sang ma, sang tai, lang mai
sach ky » sac ky, sach ty, sach kem
hanh va » hang va, hanh vi
va hanh » van hanh, va thanh, va danh
cam tuc » cam xuc, cam tu, nam thuc
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu van
mai hoi » mai khoi, dai hoi, lai hoi
tuc va » thuc va, truc va, tuc xa
va cua » va chua, via cua, ca cua

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 y)) sang mai hoi. ((hieu ve) or (hieu va)) cam tuc va hanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sach y)) sang mai hoi. ((hieu ve) OR (hieu va)) cam tuc va hanh va cua tre.
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) or (sach y)) sang mai hoi. ((hieu ve) or (hieu va)) cam tuc va hanh va cua tre*.