Perhaps you should try some spelling variations:
nhieu viec » hieu viec, nhien viet
viec cac » vien cac, viec cua, viec lam
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
tu sach » thu sach, te sach, tu cach
su sach » so sach, vu sach
nang xa » nang x, lang xa, nang ma
va tinh » may tinh
tinh ve » trinh ve, tinh ven, dinh ve
cua tre » cua te, cuu tre, cua triet
ve cua » le cua, de cua, te cua

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) or (thu hoach))) or (su sach)) ky nang xa hoi. nhieu viec cac nuoc va tinh ve cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((((tu sach) OR (thu hoach))) OR (su sach)) ky nang xa hoi. nhieu viec cac nuoc va tinh ve cua tre.
• Adding a wildcard symbol may retrieve word variants: ((((tu sach) or (thu hoach))) or (su sach)) ky nang xa hoi. nhieu viec cac nuoc va tinh ve cua tre*.