Perhaps you should try some spelling variations:
dua tren » dung tren
van hanh » van thanh, ban hanh, van anh
sang tao » hang tai
dao xuc » dao duc, dao tuc, dao xu
xuc van » duc van, luc van, vuc van
hieu va » lieu va, hieu qua
sach va » sach xa, sach ha, sach dao
tao hoi » tao khoi, tao boi, tay hoi
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) or (sach nha)) sang tao hoi. hieu va dao xuc van hanh vi ((dua tren) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach va) OR (sach nha)) sang tao hoi. hieu va dao xuc van hanh vi ((dua tren) OR (cua te)).
• Adding a wildcard symbol may retrieve word variants: tu ((sach va) or (sach nha)) sang tao hoi. hieu va dao xuc van hanh vi ((dua tren) or (cua te))*.