Perhaps you should try some spelling variations:
trinh viet » ninh viet, trinh vat
viet cua » viec cua, viet ca, viet qua
sach thu » sach thue, sach thieu, sach tham
va trinh » van trinh, va tinh, lap trinh
cac duc » cac du, cao duc, cac dac
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
sach ty » sach y, sach tu, xach tay
ve cac » va cac, vien cac
ma hoi » mai hoi, xa hoi, me hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sach ty) OR (sach thu)) xang ((ma hoi) or (ma hoa)). hieu ve cac duc va trinh viet cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ty) OR (sach thu)) xang ((ma hoi) OR (ma hoa)). hieu ve cac duc va trinh viet cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach ty) OR (sach thu)) xang ((ma hoi) or (ma hoa)). hieu ve cac duc va trinh viet cua tre*".