Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cua triet, dua tren
luc van » luoc van, luu van, duc van
cam luc » cam xuc, cau luc
cuu tre » cau tren, cau treo
hieu va » lieu va, hieu qua
hieu ve » hieu van
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang

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 tang xa hoi. ((hieu ve) OR (hieu va)) cam luc van hanh vi ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky tang xa hoi. ((hieu ve) OR (hieu va)) cam luc van hanh vi ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky tang xa hoi. ((hieu ve) OR (hieu va)) cam luc van hanh vi ((cua tre) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky tang xa hoi. ((hieu ve) OR (hieu va)) cam luc van hanh vi ((cua tre) or (cuu tre))*.