Perhaps you should try some spelling variations:
trinh viet » ninh viet, trinh vat
hieu van » hieu va, thien van, lieu va
tinh va » tich va, trinh van, trinh vat
cam cua » ca cua, nam cua, cau cua
tu sach » thu sach, su sach, te sach
hieu ve » hieu va
lang ha » long ha
cua tre » cua te, cuu tre, cua triet
sach o » sach lo, sac o, sach y
ha hoi » hoa hoi, ha noi, xa hoi
o lang » hoa lang, hoi lang

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach o lang ha hoi. ((hieu ve) or (hieu van)) cam cua ban ((trinh viet) or (tinh va)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach o lang ha hoi. ((hieu ve) OR (hieu van)) cam cua ban ((trinh viet) OR (tinh va)) cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach o lang ha hoi. ((hieu ve) or (hieu van)) cam cua ban ((trinh viet) or (tinh va)) cua tre*.