Perhaps you should try some spelling variations:
nhieu viec » hieu viec, nhien viet
trinh di » trinh do, trinh dien, trinh dinh
viec cam » viec lam, viec cua, viec va
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cua triet, dua tren
cuu tre » cau tren, cau treo
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang
tuc va » thuc va, truc va, tuc xa
xuc va » duc va, luc va, xac va

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 ky tang xa hoi. nhieu viec cam ((xuc va) OR (tuc va)) trinh di ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky tang xa hoi. nhieu viec cam ((xuc va) OR (tuc va)) trinh di ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky tang xa hoi. nhieu viec cam ((xuc va) OR (tuc va)) trinh di ((cua tre) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky tang xa hoi. nhieu viec cam ((xuc va) OR (tuc va)) trinh di ((cua tre) or (cuu tre))*.