Perhaps you should try some spelling variations:
nhieu viec » nhien viet
sach duoc » sach nuoc, sach dao, sach dung
hieu viec » hieu ve, sieu viet, hieu hien
cua viet » ca viet, hoa viet, cua dieu
nang dai » nang dau, nang tai, lang dai
dai khoa » da khoa, tai khoa, dac khoa
hanh vai » hanh vi, hanh va, hanh tai
vai cua » dai cua, hai cua, lai cua
va hanh » van hanh, va thanh, va danh
tu sach » thu sach, su sach, te sach
duoc va » nuoc va, duc va, duoc ma
sach tu » sach thu, cach tu, sach ty
tu nang » tru nang, tu nong, tu nano

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 tu nang dai khoa. ((hieu viec) OR (nhieu viec)) sach duoc va hanh vai cua viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach tu nang dai khoa. ((hieu viec) OR (nhieu viec)) sach duoc va hanh vai cua viet".
• Adding a wildcard symbol may retrieve word variants: tu sach tu nang dai khoa. ((hieu viec) OR (nhieu viec)) sach duoc va hanh vai cua viet*.