Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
thu sach » tu sach, thuat sach, thuoc sach
dinh du » dinh duc, dinh cu, dinh tu
dinh di » dinh vi, danh di, dinh da
nam xuc » cam xuc, nam xua, nam thuc
tu cach » tu cac
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang
cua tre » cua te, cuu tre, cua triet
xuc va » duc va, tuc va, luc va

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 (thu sach)) ky tang xa hoi. hieu van nam xuc va ((dinh di) OR (dinh du)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu cach) OR (thu sach)) ky tang xa hoi. hieu van nam xuc va ((dinh di) OR (dinh du)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu cach) or (thu sach)) ky tang xa hoi. hieu van nam xuc va ((dinh di) OR (dinh du)) cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu cach) or (thu sach)) ky tang xa hoi. hieu van nam xuc va ((dinh di) OR (dinh du)) cua tre*.