Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
luoc van » luoc can, luoc va, luot van
sach ky » sac ky, sach y, sach ty
ky tang » ky nang, ky dang, kho tang
tang xa » trang xa, tang ma, lang xa
hieu va » lieu va, hieu qua
luc van » luu van, duc van, luc va
cua tre » cua te, cua triet, dua tren
cuu tre » cau tren, cau treo

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky tang xa hoi. hieu va cac ((luc van) OR (luoc van)) lanh dao ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky tang xa hoi. hieu va cac ((luc van) OR (luoc van)) lanh dao ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky tang xa hoi. hieu va cac ((luc van) OR (luoc van)) lanh dao ((cua tre) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: thu sach ky tang xa hoi. hieu va cac ((luc van) OR (luoc van)) lanh dao ((cua tre) or (cuu tre))*.