Perhaps you should try some spelling variations:
nhieu viec » hieu viec, nhien viet
tinh doi » trinh doc, trinh do, tinh hoc
viec cam » viec lam, viec cua, viec va
thu sach » tu sach, thuat sach, thuoc sach
lang ha » long ha
sach ky » sac ky, sach y, sach ty
lang xa » dang xay, lang van
tinh di » trinh di, tinh da, tin di
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky ((lang xa) or (lang ha)) hoi. nhieu viec cam xuc hay ((tinh di) or (tinh doi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky ((lang xa) OR (lang ha)) hoi. nhieu viec cam xuc hay ((tinh di) OR (tinh doi)) cua tre.
• Adding a wildcard symbol may retrieve word variants: thu sach ky ((lang xa) or (lang ha)) hoi. nhieu viec cam xuc hay ((tinh di) or (tinh doi)) cua tre*.