Perhaps you should try some spelling variations:
hieu viec » nhieu viec, hieu ve, sieu viet
van hanh » van thanh, ban hanh, van anh
viec cac » vien cac, viec cua, viec lam
sach thu » sach thue, sach thieu, sach tham
nang xa » nang x, lang xa, nang ma
sach ky » sac ky, sach y, sach ty
cac hoc » cach hoc, cac hop, bac hoc
hoc van » hoc dan, hoc va, hoc vat
vai cau » van cau, vai cac, lai chau
va cau » van cau, va cac, va dau

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) or (sach thu)) nang xa hoi. hieu viec cac hoc van hanh ((vai cau) OR (va cau)) treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sach thu)) nang xa hoi. hieu viec cac hoc van hanh ((vai cau) OR (va cau)) treo*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) or (sach thu)) nang xa hoi. hieu viec cac hoc van hanh ((vai cau) OR (va cau)) treo*".