Perhaps you should try some spelling variations:
dieu hien » dieu khien, dieu kien, bieu hien
cua viet » ca viet, hoa viet, cua vat
hang vai » hang tai, hang hai, hang vi
hien cac » thien cac, vien cac, hieu cac
vu nang » vuc nang, va nang, vu dang
cac duc » cac du, cao duc, cac dac
duc ban » duc tan, duc van, dua ban
tu sach » thu sach, su sach, te sach
v nang » va nang, van nang, voi 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 ((v nang) OR (vu nang)) x hoi. dieu hien cac duc ban ((hang vai) or (hang va)) cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((v nang) OR (vu nang)) x hoi. dieu hien cac duc ban ((hang vai) OR (hang va)) cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((v nang) OR (vu nang)) x hoi. dieu hien cac duc ban ((hang vai) or (hang va)) cua viet".
• Adding a wildcard symbol may retrieve word variants: tu sach ((v nang) OR (vu nang)) x hoi. dieu hien cac duc ban ((hang vai) or (hang va)) cua viet*.