Perhaps you should try some spelling variations:
sang mai » sang ma, sang tai, lang mai
mai khoi » mai khoa, tai khoa, cac khoi
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
ky sang » ky nang, ky dang, ky tang
hieu ve » hieu van
hieu va » lieu va, hieu qua
cam tuc » cam xuc, cam tu, nam thuc
va hanh » van hanh, va thanh, va danh
cuu tre » cua tre, cau tren, cau treo
tuc va » thuc va, truc va, tuc xa
vi cuu » vi luu, vinh cuu

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 hanh vi cuu tre~.
• 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 hanh vi cuu tre*.