Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
sach ky » sach y, sach ty, sach kem
tinh vi » trinh vi, tinh voi, tinh va
va tinh » may tinh
nam xuc » cam xuc, nam xua, nam thuc
cua tre » cua te, cuu tre, cua triet
co hoi » co hoc, co loi
sac ky » cac ky, sai ky
xuc va » duc va, tuc va, luc va
vi cua » vai cua, di cua

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