Perhaps you should try some spelling variations:
nhieu viec » hieu viec, nhien viet
sieu viet » su viet, dien viet, viet viet
bien viet » dien viet, tieng viet, trien viet
cac truc » cau truc, cac tru, cac trung
su sach » so sach, vu sach
nang ma » tang ma, sang ma, nang cao
hang di » hang doi, hang vi, hang dien
va hang » van hang, va nang, va lang
truc va » thuc va, thuc vat, trung va
di cua » dai cua, doi cua, de cua
y nang » ky nang, ly nang, v nang
ma hoi » mai hoi, xa hoi, ma hoa
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 ma hoi. ((nhieu viec) or (((sieu viet) OR (bien viet)))) cac truc va hang di cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang ma hoi. ((nhieu viec) OR (((sieu viet) OR (bien viet)))) cac truc va hang di cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang ma hoi. ((nhieu viec) or (((sieu viet) OR (bien viet)))) cac truc va hang di cua te".
• Adding a wildcard symbol may retrieve word variants: su sach y nang ma hoi. ((nhieu viec) or (((sieu viet) OR (bien viet)))) cac truc va hang di cua te*.