Perhaps you should try some spelling variations:
hieu viec » nhieu viec, hieu ve, sieu viet
viec dai » vien dai, viec tai, viec dat
dai luan » bai luan, dan luan, dat luan
dinh vai » dinh van, dinh vi, dinh va
va dinh » van dinh, va kinh, va tinh
luan va » luan van, luat va
te sach » toc sach
y nang » ky nang, ly nang, may nang
v nang » va nang, vu nang, van nang
cua tu » cua tuc, cua cu, cua te
cua su » qua su

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ((y nang) or (v nang)) xa hoi. hieu viec dai luan va dinh vai ((cua tu) OR (cua su))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((y nang) OR (v nang)) xa hoi. hieu viec dai luan va dinh vai ((cua tu) OR (cua su)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ((y nang) or (v nang)) xa hoi. hieu viec dai luan va dinh vai ((cua tu) OR (cua su))".
• Adding a wildcard symbol may retrieve word variants: te sach ((y nang) or (v nang)) xa hoi. hieu viec dai luan va dinh vai ((cua tu) OR (cua su))*.