Perhaps you should try some spelling variations:
hieu viec » nhieu viec, hieu ve, sieu viet
viec cac » vien cac, viec cua, viec lam
hang vai » hang tai, hang hai, hang vi
tu sach » thu sach, su sach, te sach
duc ban » duc van, dua ban, duc man
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
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 y nang x hoi. hieu viec cac ((duc ban) OR (duc tan)) ((hang vai) or (hang va)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang x hoi. hieu viec cac ((duc ban) OR (duc tan)) ((hang vai) OR (hang va)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang x hoi. hieu viec cac ((duc ban) OR (duc tan)) ((hang vai) or (hang va)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang x hoi. hieu viec cac ((duc ban) OR (duc tan)) ((hang vai) or (hang va)) cua tre*.