Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
dao lang » dao khang, dao quang, dao trang
tu cach » tu cac
hieu va » lieu va, hieu qua
dan dai » dat dai, can dai, dan dat
cao duc » dao duc, cao suc, giao duc
hieu ve » hieu van
lang xa » lang ha, dang xay, lang van
va dan » ca dan, va dao, va dau
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 cach) or (toc sach)) dao lang xa hoi. ((hieu ve) or (hieu va)) cao duc va dan dai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu cach) OR (toc sach)) dao lang xa hoi. ((hieu ve) OR (hieu va)) cao duc va dan dai cua te.
• Adding a wildcard symbol may retrieve word variants: ((tu cach) or (toc sach)) dao lang xa hoi. ((hieu ve) or (hieu va)) cao duc va dan dai cua te*.