Perhaps you should try some spelling variations:
hieu viec » nhieu viec, hieu ve, sieu viet
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
ly nang » ky nang, ly hang, ly vang
hanh va » hang va, hanh vi
cuu tre » cau tren, cau treo
cua tre » cua te, cua triet, dua tren
y nang » ky nang, v nang, may nang
cua lo » cua lao, cua loc, cua lop
lo van » le van, vo van, so van

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 ((y nang) OR (ly nang)) xa hoi. hieu viec cua lo van hanh va ((cuu tre) or (cua tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((y nang) OR (ly nang)) xa hoi. hieu viec cua lo van hanh va ((cuu tre) OR (cua tre))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((y nang) OR (ly nang)) xa hoi. hieu viec cua lo van hanh va ((cuu tre) or (cua tre))*".