Perhaps you should try some spelling variations:
ninh viet » sinh vien, anh viet
hieu van » hieu va, thien van, lieu va
quy ninh » quy dinh, qua ninh, quy trinh
van cac » van hac, van cau, van bac
cua tre » cuu tre, cua triet, dua tren
duc quy » duc duy, duc huy, duy quy
cac duc » cac du, cao duc, cac dac
te sach » toc sach
sach ty » sach y, sach tu, sach thu
tang ma » mang may, tang van
hang ma » hang va, hang ca, nang ma
cua te » cua tu

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

• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty ((hang ma) OR (tang ma)) hoi. hieu van cac duc quy ninh viet ((cua tre) OR (cua te))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty ((hang ma) OR (tang ma)) hoi. hieu van cac duc quy ninh viet ((cua tre) or (cua te))~".
• Adding a wildcard symbol may retrieve word variants: te sach ty ((hang ma) OR (tang ma)) hoi. hieu van cac duc quy ninh viet ((cua tre) or (cua te))*.