Perhaps you should try some spelling variations:
sang mai » sang ma, sang tai, lang mai
mai khoi » mai khoa, tai khoa, cac khoi
hanh vai » hanh vi, hanh va, hanh tai
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
vai cuu » vai cua
cuu tre » cua tre, cau tren, cau treo
hieu va » lieu va, hieu qua
hieu ve » hieu van
ky sang » ky nang, ky dang, ky tang
luc va » duc va, loc va
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: su sach ky sang mai khoi. ((hieu ve) or (hieu va)) cam ((luc va) OR (tuc va)) hanh vai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky sang mai khoi. ((hieu ve) OR (hieu va)) cam ((luc va) OR (tuc va)) hanh vai cuu tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky sang mai khoi. ((hieu ve) or (hieu va)) cam ((luc va) OR (tuc va)) hanh vai cuu tre*".