Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
cua tre » cuu tre, cua triet, dua tren
xuc van » duc van, luc van, vuc van
dao xuc » dao duc, dao tuc, dao xu
sach va » sach xa, sach ha, sach dao
hieu va » lieu va, hieu qua
sang ma » tang ma, sang tao, mang may
nang ma » tang ma, nang cao, mang may
va dao » ca 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: tu sach va ((nang ma) OR (sang ma)) hoi. hieu va dao xuc van hanh vi ((cua tre) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach va ((nang ma) OR (sang ma)) hoi. hieu va dao xuc van hanh vi ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach va ((nang ma) OR (sang ma)) hoi. hieu va dao xuc van hanh vi ((cua tre) or (cua te))".
• Adding a wildcard symbol may retrieve word variants: tu sach va ((nang ma) OR (sang ma)) hoi. hieu va dao xuc van hanh vi ((cua tre) or (cua te))*.