Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
cua tre » cuu tre, cua triet, dua tren
va nang » van nang, da nang, cam nang
va lang » hoa lang
cac tuc » cac toc, cac tu, cac tac
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
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 lang xa hoi. hieu va cac tuc ((va lang) OR (va nang)) tai ((cua tre) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky lang xa hoi. hieu va cac tuc ((va lang) OR (va nang)) tai ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky lang xa hoi. hieu va cac tuc ((va lang) OR (va nang)) tai ((cua tre) or (cua te))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky lang xa hoi. hieu va cac tuc ((va lang) OR (va nang)) tai ((cua tre) or (cua te))*.