Perhaps you should try some spelling variations:
kho tang » cao tang
tu sach » thu sach, su sach, te sach
cuu tre » cau tren, cau treo
va hanh » van hanh, va thanh, va danh
cam luc » cam xuc, cau luc
hieu va » lieu va, hieu qua
ky tang » ky nang, ky dang, ky trong
cua tre » cua te, cua triet, dua tren
va cam » va cham, va cac, va cao
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: tu sach ((ky tang) OR (kho tang)) xa hoi. hieu va cam luc va hanh vi ((cuu tre) or (cua tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky tang) OR (kho tang)) xa hoi. hieu va cam luc va hanh vi ((cuu tre) OR (cua tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky tang) OR (kho tang)) xa hoi. hieu va cam luc va hanh vi ((cuu tre) or (cua tre))".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky tang) OR (kho tang)) xa hoi. hieu va cam luc va hanh vi ((cuu tre) or (cua tre))*.