Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
sach ty » sach tu, sach thu, xach tay
kinh ve » kinh te, dinh ve, minh ve
va kinh » va tinh, qua kinh
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va
xang xa » lang xa, mang xa, ang xa
xuc va » duc va, tuc va, luc va
ve cua » le cua, de cua, te cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc ((sach ty) OR (sach y)) xang xa hoi. ((hieu ve) or (hieu van)) cam xuc va kinh ve cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((sach ty) OR (sach y)) xang xa hoi. ((hieu ve) OR (hieu van)) cam xuc va kinh ve cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((sach ty) OR (sach y)) xang xa hoi. ((hieu ve) or (hieu van)) cam xuc va kinh ve cua tre".
• Adding a wildcard symbol may retrieve word variants: doc ((sach ty) OR (sach y)) xang xa hoi. ((hieu ve) or (hieu van)) cam xuc va kinh ve cua tre*.