Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
sang mai » sang ma, sang tai, lang mai
mai khoi » mai khoa, tai khoa, cac khoi
hieu van » thien van, lieu va, hieu ve
hanh vai » hanh vi, hanh va, hanh tai
va hanh » van hanh, va thanh, va danh
cuu tre » cua tre, cau treo
su sach » so sach, vu sach
cam luc » cam xuc, cau luc
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
ky sang » ky nang, ky dang, ky tang
luc va » duc va, tuc va, loc va

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 van) or (hieu va)) cam luc va hanh vai ((cuu tre) OR (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky sang mai khoi. ((hieu van) OR (hieu va)) cam luc va hanh vai ((cuu tre) OR (cau tren))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky sang mai khoi. ((hieu van) or (hieu va)) cam luc va hanh vai ((cuu tre) OR (cau tren))*".