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
cua tre » cua te, cuu tre, cua triet
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
hieu ve » hieu va
nang ma » tang ma, sang ma, nang cao
ty nang » ky nang, ty xang, ty hang
ma hoi » mai hoi, xa hoi, ma hoa
cua tu » cua tuc, cua su, cua cu

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