Perhaps you should try some spelling variations:
hieu viec » nhieu viec, hieu ve, sieu viet
viec cac » vien cac, viec cua, viec lam
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
su sach » so sach, vu sach
nam dan » nam dinh
cua tre » cuu tre, cua triet, dua tren
cam dan » cac dan, ca dan, cay dan
nang xa » nang x, lang xa, nang ma
y nang » ky nang, ly nang, v nang
cua te » cua tu

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

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