Perhaps you should try some spelling variations:
sang mai » sang ma, sang tai, lang mai
mai khoi » mai khoa, tai khoa, cac khoi
va thanh » gia thanh, ban thanh, va tinh
tu sach » thu sach, su sach, te sach
cam tuc » cam xuc, cam tu, nam thuc
van cua » vang cua, ban cua, nan cua
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
hieu ve » hieu van
ky sang » ky nang, ky dang, ky tang
dan cua » dan ca, ban cua, dai cua
tuc va » thuc va, truc va, tuc xa

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky sang mai khoi. ((hieu ve) or (hieu va)) cam tuc va thanh ((van cua) OR (dan cua)) vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky sang mai khoi. ((hieu ve) OR (hieu va)) cam tuc va thanh ((van cua) OR (dan cua)) vat.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky sang mai khoi. ((hieu ve) or (hieu va)) cam tuc va thanh ((van cua) OR (dan cua)) vat".
• Adding a wildcard symbol may retrieve word variants: tu sach ky sang mai khoi. ((hieu ve) or (hieu va)) cam tuc va thanh ((van cua) OR (dan cua)) vat*.