Perhaps you should try some spelling variations:
trinh voi » trinh hoi, trinh vi, trinh boi
tinh voi » tinh doi, binh voi, minh voi
hieu van » hieu va, thien van, lieu va
su sach » so sach, vu sach
cau xuc » cam xuc, cau luc, cau truc
van cau » van dau, van hau, van chat
sach ty » sach y, sach tu, sach thu
nang xa » nang x, lang xa, nang ma
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: su sach ty ((nang xa) or (nang cao)) hoi. hieu van cau xuc va ((tinh voi) OR (trinh voi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty ((nang xa) OR (nang cao)) hoi. hieu van cau xuc va ((tinh voi) OR (trinh voi)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty ((nang xa) or (nang cao)) hoi. hieu van cau xuc va ((tinh voi) OR (trinh voi)) cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ty ((nang xa) or (nang cao)) hoi. hieu van cau xuc va ((tinh voi) OR (trinh voi)) cua tre*.