Perhaps you should try some spelling variations:
dang hanh » dang thanh, ban hanh, dang van
dan hanh » dan khanh, dan thanh, ban hanh
hieu van » hieu va, thien van, lieu va
cuu thuc » cuu tac
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
van cuu » van cau, van chu, van cu
cua tu » cua tuc, cua cu, cua te
cua su » qua su
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky nang x hoi. hieu van cuu thuc ((dan hanh) OR (dang hanh)) ve ((cua tu) or (cua su))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x hoi. hieu van cuu thuc ((dan hanh) OR (dang hanh)) ve ((cua tu) OR (cua su)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang x hoi. hieu van cuu thuc ((dan hanh) OR (dang hanh)) ve ((cua tu) or (cua su))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x hoi. hieu van cuu thuc ((dan hanh) OR (dang hanh)) ve ((cua tu) or (cua su))*.