Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
cam thue » cam thu, lam thue, nam thue
sang tao » hang tai
tang tai » hang tai, dung tai, dong tai
hieu va » lieu va, hieu qua
thue va » thuc va, thuyet va, thuc vat
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet
tu sach » thu sach, su sach, te sach
va cam » va cham, va cac, va cao
y nang » ky nang, ly nang, v nang

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 tai) OR (sang tao)) ((cua tre) or (va 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 tai) OR (sang tao)) ((cua tre) OR (va 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 tai) OR (sang tao)) ((cua tre) or (va triet))".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang xa hoi. hieu va cam thue va ((tang tai) OR (sang tao)) ((cua tre) or (va triet))*.