Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc 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 hang » van hang, va lang, va hanh
cao suc » cao su, cao duc
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
va cao » va cac, va co, va dao
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: toc sach ky lang xa hoi. lieu va cao suc ((va hang) OR (va nang)) tai ((cua tre) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky lang xa hoi. lieu va cao suc ((va hang) OR (va nang)) tai ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky lang xa hoi. lieu va cao suc ((va hang) OR (va nang)) tai ((cua tre) or (cua te))".
• Adding a wildcard symbol may retrieve word variants: toc sach ky lang xa hoi. lieu va cao suc ((va hang) OR (va nang)) tai ((cua tre) or (cua te))*.