Perhaps you should try some spelling variations:
trinh viet » ninh viet, trinh vat
dinh viet » ninh viet, danh viet, sinh vien
te sach » toc sach
sach ty » sach y, sach tu, sach thu
cuu tre » cua tre, cau tren, cau treo
hieu ve » hieu va, hieu van
nang ma » tang ma, sang ma, nang cao
xang ma » tang ma, sang ma, rang ma
dan va » doan va, dan ca, ban va
ve cac » va cac, vien cac

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 ((xang ma) OR (nang ma)) hoi. hieu ve cac dan va ((dinh viet) or (trinh viet)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty ((xang ma) OR (nang ma)) hoi. hieu ve cac dan va ((dinh viet) OR (trinh viet)) cuu tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty ((xang ma) OR (nang ma)) hoi. hieu ve cac dan va ((dinh viet) or (trinh viet)) cuu tre*".