Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
vu sach » vu bach, su sach, vu khach
cua tre » cua te, cua triet, dua tren
tinh vi » trinh vi, tinh voi, tinh va
va tinh » may tinh
sach ky » sac ky, sach y, sach ty
nam xuc » cam xuc, nam xua, nam thuc
cuu tre » cau tren, cau treo
xuc va » duc va, tuc va, luc va
co hoi » co hoc, co loi

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ky nang ((co hoi) or (xa hoi)). hieu van nam xuc va tinh vi ((cua tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky nang ((co hoi) OR (xa hoi)). hieu van nam xuc va tinh vi ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky nang ((co hoi) or (xa hoi)). hieu van nam xuc va tinh vi ((cua tre) OR (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: vu sach ky nang ((co hoi) or (xa hoi)). hieu van nam xuc va tinh vi ((cua tre) OR (cuu tre))*.