Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
va trang » va trung, va thanh, va nang
cam thue » cam thu, lam thue, nam thue
cua tre » cua te, cuu tre, dua tren
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
va tang » van tang, ha tang, va nang
y nang » ky nang, ly nang, v nang
va cam » va cham, va cac, va cao

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