Perhaps you should try some spelling variations:
vanh dai » van dai, vanh tai, lanh dao
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
cua tre » cuu tre, cua triet, dua tren
va cam » va cham, va cac, va cao
tuc va » thuc va, truc va, duc va
cua te » cua tu

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