Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
hieu van » hieu va, thien van, lieu va
lam duoc » nam duoc, luat duoc, lam thuoc
lam xuc » cam xuc
sach ky » sac ky, sach y, sach ty
ban anh » ban hanh, ban banh, ban danh
cua tre » cua te, cuu tre, cua triet
tu sach » thu sach, su sach, te sach
anh vi » hanh vi, anh va, anh ve
x hoi » xa hoi, o hoi, x ho

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 nang x hoi. hieu van ((lam xuc) OR (lam duoc)) ban anh vi ((cua tre) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x hoi. hieu van ((lam xuc) OR (lam duoc)) ban anh vi ((cua tre) OR (cau tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang x hoi. hieu van ((lam xuc) OR (lam duoc)) ban anh vi ((cua tre) or (cau tren))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x hoi. hieu van ((lam xuc) OR (lam duoc)) ban anh vi ((cua tre) or (cau tren))*.