Perhaps you should try some spelling variations:
su sach » so sach, vu sach
sach ly » sach y, sach lo, sach ty
vang xa » lang xa, ang xa, dang xay
mang xa » lang xa, mang may, dang xay
hieu le » hieu ve, hieu he, hieu ly
danh vi » dinh vi, danh di, danh va
cua tre » cua te, cuu tre, cua triet
le dat » le dan, de dat, le dac
nuoc » quoc, duoc, ngoc

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ly ((vang xa) OR (mang xa)) hoi. hieu le dat nuoc va ((danh vi) or (hanh vi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ly ((vang xa) OR (mang xa)) hoi. hieu le dat nuoc va ((danh vi) OR (hanh vi)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ly ((vang xa) OR (mang xa)) hoi. hieu le dat nuoc va ((danh vi) or (hanh vi)) cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ly ((vang xa) OR (mang xa)) hoi. hieu le dat nuoc va ((danh vi) or (hanh vi)) cua tre*.