Perhaps you should try some spelling variations:
dan thanh » dang thanh, danh thanh, ban thanh
hieu van » hieu va, thien van, hieu ve
thanh de » hanh de, thanh ve, thanh do
su sach » so sach, vu sach
ty nang » ty xang, ty hang, ly nang
thu dan » thuc dan, thu dang, thu ban
de cua » le cua, te cua, dieu cua
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ((ty nang) or (ky nang)) xa hoi. ((hieu van) OR (lieu va)) nam thu dan thanh de cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ty nang) OR (ky nang)) xa hoi. ((hieu van) OR (lieu va)) nam thu dan thanh de cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((ty nang) or (ky nang)) xa hoi. ((hieu van) OR (lieu va)) nam thu dan thanh de cua te".
• Adding a wildcard symbol may retrieve word variants: su sach ((ty nang) or (ky nang)) xa hoi. ((hieu van) OR (lieu va)) nam thu dan thanh de cua te*.